Test just one version in the 6.x series

7.x is the only officially supported version of Rails, so let's focus on
those versions. While we still support 6.x for now, we don't need to
test on more than one version of it.

.github/workflows/ruby.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rails-version: ['5.2.8.1', '6.0.3.7', '6.1.7.6', '7.0.8', '7.1.2', 'main']
+        rails-version: ['5.2.8.1', '6.1.7.6', '7.0.8', '7.1.2', 'main']
         ruby-version: ['2.7', '3.0', '3.1', '3.2']
         exclude:
           - rails-version: '5.2.5'

README.rdoc

@@ -6,7 +6,7 @@ This gem hooks into the Rack middleware of Rails. This way all paths are downcas
 
 == Requirements
 
-This gem is tested with 5.2.x, 6.0.x, 6.1.x., 7.x. It reportedly also works with Sinatra, although I do not use Sinatra myself. Sinatra test-cases will be most welcome.
+This gem is tested with 5.2.x, 6.x, 7.x. It reportedly also works with Sinatra, although I do not use Sinatra myself. Sinatra test-cases will be most welcome.
 
 It has previously worked - and I presume still works - in Rails 5.0.x and 5.1.x.