add try catch

src/fetch-wrapper.ts

@@ -153,7 +153,14 @@ export default function fetchWrapper(
 async function getResponseData(response: Response) {
   const contentType = response.headers.get("content-type");
   if (/application\/json/.test(contentType!)) {
-    return response.json();
+    // In the event that we get an empty response body we fallback to
+    // using .text(), but this should be investigated since if this were
+    // to occur in the GitHub API it really should not return an empty body.
+    try {
+      return response.json();
+    } catch (e) {
+      return response.text();
+    }
   }
 
   if (!contentType || /^text\/|charset=utf-8$/.test(contentType)) {