Use the released ruby 2.4, not an rc

Author: jrafanie

.travis.yml

@@ -6,7 +6,7 @@ rvm:
   - 2.1.10
   - 2.2.6
   - 2.3.3
-  - 2.4.0-rc1
+  - 2.4.1
 gemfile:
   - gemfiles/rails_3.gemfile
   - gemfiles/rails_4.gemfile
@@ -23,13 +23,13 @@ matrix:
       gemfile: gemfiles/rails_3.gemfile
     - rvm: 2.3.3
       gemfile: gemfiles/rails_3.gemfile
-    - rvm: 2.4.0-rc1
+    - rvm: 2.4.1
       gemfile: gemfiles/rails_3.gemfile
-    - rvm: 2.4.0-rc1
+    - rvm: 2.4.1
       gemfile: gemfiles/rails_4.gemfile
-    - rvm: 2.4.0-rc1
+    - rvm: 2.4.1
       gemfile: gemfiles/rails_4.1.gemfile
-    - rvm: 2.4.0-rc1
+    - rvm: 2.4.1
       gemfile: gemfiles/rails_4.2.gemfile
 before_install:
   - gem install bundler