Add rails 6.1 support

.travis.yml

@@ -4,6 +4,7 @@ rvm:
 - 2.6
 - 2.5
 gemfile:
+- gemfiles/rails_61.gemfile
 - gemfiles/rails_60.gemfile
 - gemfiles/rails_52.gemfile
 matrix:
@@ -20,12 +21,5 @@ matrix:
     gemfile: gemfiles/rails_52.gemfile
   - rvm: 2.3
     gemfile: gemfiles/rails_52.gemfile
-  # future rails
-  - rvm: 2.5
-    gemfile: gemfiles/rails_61.gemfile
-  # Allow rails 6.1 to fail while master branch is used
-  allow_failures:
-  - rvm: 2.5
-    gemfile: gemfiles/rails_61.gemfile
 notifications:
   email: false