diff --git a/spec/fixtures/vcr_cassettes/Doi/register_doi/should_change_url.yml b/spec/fixtures/vcr_cassettes/Doi/register_doi/should_change_url.yml
index a83908c47..4381bfd75 100644
--- a/spec/fixtures/vcr_cassettes/Doi/register_doi/should_change_url.yml
+++ b/spec/fixtures/vcr_cassettes/Doi/register_doi/should_change_url.yml
@@ -27,11 +27,11 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.5438/MCNV-GA6N"}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:28:17 GMT
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.5438/MCNV-GA6N?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.5438/MCNV-GA6N?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -65,6 +65,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.5438/MCNV-GA6N","values":[{"index":1,"type":"URL","data":{"format":"string","value":"https://blog.datacite.org/re3data-science-europe/"},"ttl":86400,"timestamp":"2018-07-30T07:53:49Z"}]}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:28:17 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/Doi/register_doi/should_register.yml b/spec/fixtures/vcr_cassettes/Doi/register_doi/should_register.yml
index 4ee50df27..283a05692 100644
--- a/spec/fixtures/vcr_cassettes/Doi/register_doi/should_register.yml
+++ b/spec/fixtures/vcr_cassettes/Doi/register_doi/should_register.yml
@@ -27,11 +27,11 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.5438/MCNV-GA6N"}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:28:15 GMT
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.5438/MCNV-GA6N?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.5438/MCNV-GA6N?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -65,6 +65,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.5438/MCNV-GA6N","values":[{"index":1,"type":"URL","data":{"format":"string","value":"https://blog.datacite.org/re3data-science-europe/"},"ttl":86400,"timestamp":"2018-07-30T07:53:49Z"}]}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:28:16 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_status_code_200.yml b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_status_code_200.yml
index 823837ea8..f7eeaa880 100644
--- a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_status_code_200.yml
+++ b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_status_code_200.yml
@@ -2,7 +2,7 @@
 http_interactions:
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.5438/8SYZ-YM47?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.5438/8SYZ-YM47?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -36,6 +36,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.5438/8SYZ-YM47","values":[{"index":1,"type":"URL","data":{"format":"string","value":"https://blog.datacite.org/welcome-helena-cousijn/"},"ttl":86400,"timestamp":"2018-07-29T23:57:59Z"}]}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:48:02 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_url.yml b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_url.yml
index 22a559893..0b83593e9 100644
--- a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_url.yml
+++ b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url/returns_url.yml
@@ -2,7 +2,7 @@
 http_interactions:
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.5438/8SYZ-YM47?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.5438/8SYZ-YM47?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -36,6 +36,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.5438/8SYZ-YM47","values":[{"index":1,"type":"URL","data":{"format":"string","value":"https://blog.datacite.org/welcome-helena-cousijn/"},"ttl":86400,"timestamp":"2018-07-29T23:57:59Z"}]}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:48:01 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_not_DataCite_DOI.yml b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_not_DataCite_DOI.yml
index 42687b259..7841988d8 100644
--- a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_not_DataCite_DOI.yml
+++ b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_not_DataCite_DOI.yml
@@ -2,7 +2,7 @@
 http_interactions:
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.1371/JOURNAL.PBIO.2001414?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.1371/JOURNAL.PBIO.2001414?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -36,6 +36,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.1371/JOURNAL.PBIO.2001414","values":[{"index":1,"type":"URL","data":{"format":"string","value":"http://dx.plos.org/10.1371/journal.pbio.2001414"},"ttl":86400,"timestamp":"2017-06-29T17:30:17Z"}]}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:48:13 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_200.yml b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_200.yml
index 73b622063..8702b434c 100644
--- a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_200.yml
+++ b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_200.yml
@@ -2,7 +2,7 @@
 http_interactions:
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.1371/JOURNAL.PBIO.2001414?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.1371/JOURNAL.PBIO.2001414?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -36,6 +36,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.1371/JOURNAL.PBIO.2001414","values":[{"index":1,"type":"URL","data":{"format":"string","value":"http://dx.plos.org/10.1371/journal.pbio.2001414"},"ttl":86400,"timestamp":"2017-06-29T17:30:17Z"}]}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:53:52 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_500.yml b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_500.yml
index b5f19e841..a7d07951c 100644
--- a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_500.yml
+++ b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_DataCite_DOI/returns_status_code_500.yml
@@ -2,7 +2,7 @@
 http_interactions:
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.1371/JOURNAL.PBIO.2001414?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.1371/JOURNAL.PBIO.2001414?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -36,6 +36,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":1,"handle":"10.1371/JOURNAL.PBIO.2001414","values":[{"index":1,"type":"URL","data":{"format":"string","value":"http://dx.plos.org/10.1371/journal.pbio.2001414"},"ttl":86400,"timestamp":"2017-06-29T17:30:17Z"}]}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:48:14 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_not_found.yml b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_not_found.yml
index 2c1e35b0d..75bd7c16f 100644
--- a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_not_found.yml
+++ b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_not_found.yml
@@ -2,7 +2,7 @@
 http_interactions:
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.14454/61Y1-E521?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.14454/61Y1-E521?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -36,6 +36,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":100,"handle":"10.14454/61Y1-E521"}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:48:09 GMT
 recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_status_code_404.yml b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_status_code_404.yml
index 8d4e05651..94572acb1 100644
--- a/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_status_code_404.yml
+++ b/spec/fixtures/vcr_cassettes/dois/GET_/dois/DOI/get-url_not_found/returns_status_code_404.yml
@@ -2,7 +2,7 @@
 http_interactions:
 - request:
     method: get
-    uri: https://doi.org/api/handles/10.14454/61Y1-E521?index=1
+    uri: https://38.100.138.135:8000/api/handles/10.14454/61Y1-E521?index=1
     body:
       encoding: US-ASCII
       string: ''
@@ -36,6 +36,6 @@ http_interactions:
     body:
       encoding: ASCII-8BIT
       string: '{"responseCode":100,"handle":"10.14454/61Y1-E521"}'
-    http_version: 
+    http_version:
   recorded_at: Mon, 30 Jul 2018 18:48:10 GMT
 recorded_with: VCR 3.0.3