.travis.yml in devise-two-factor-3.0.0 vs .travis.yml in devise-two-factor-3.0.1

@@ -2,9 +2,22 @@
 language: ruby
 cache: bundler
 before_install:
   - gem update --system
   - gem update bundler
+gemfile:
+  - Gemfile
+  - gemfiles/rails_4_1.gemfile
+  - gemfiles/rails_4_2.gemfile
+  - gemfiles/rails_5_0.gemfile
 rvm:
   - "2.1"
   - "2.2"
-  - "2.3.0"
+  - "2.3.4"
+  - "2.4.0"
+  - "2.4.1"
+matrix:
+  exclude:
+    - rvm: "2.1"
+      gemfile: gemfiles/rails_5_0.gemfile
+    - rvm: "2.2"
+      gemfile: gemfiles/rails_5_0.gemfile