Add support for Rails 8 (#442)

* Remove useless require
* Add support for Rails 8.0

.github/workflows/ci.yml

@@ -92,6 +92,7 @@ jobs:
           - '2.7'
           - '2.6'
         rails:
+          - rails_8.0
           - rails_7.2
           - rails_7.1
           - rails_7.0
@@ -114,6 +115,15 @@ jobs:
           - ruby: '3.0'
             rails: 'rails_7.2'
 
+          - ruby: '2.6'
+            rails: 'rails_8.0'
+          - ruby: '2.7'
+            rails: 'rails_8.0'
+          - ruby: '3.0'
+            rails: 'rails_8.0'
+          - ruby: '3.1'
+            rails: 'rails_8.0'
+
     env: # $BUNDLE_GEMFILE must be set at the job level, so it is set for all steps
       BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/${{ matrix.rails }}.gemfile
 

.rspec

@@ -1,2 +1 @@
---require spec_helper
---warnings
+--warnings