.travis.yml in mongoid-locker-0.3.5 vs .travis.yml in mongoid-locker-0.3.6

@@ -9,19 +9,21 @@
   - gem update --system
   - gem install bundler
 
 matrix:
   include:
-    - rvm: 2.3.1
-      env: MONGOID_VERSION=2
-    - rvm: 2.3.1
-      env: MONGOID_VERSION=3
-    - rvm: 2.3.1
+    - rvm: 2.3.6
       env: MONGOID_VERSION=4
-    - rvm: 2.3.1
+    - rvm: 2.3.6
       env: MONGOID_VERSION=5
-    - rvm: 2.3.1
+    - rvm: 2.3.6
       env: MONGOID_VERSION=6
+    - rvm: 2.4.3
+      env: MONGOID_VERSION=6
+    - rvm: 2.4.3
+      env: MONGOID_VERSION=7
+    - rvm: 2.5.0
+      env: MONGOID_VERSION=7
       before_script:
         - bundle exec danger
     - rvm: rbx-2
     - rvm: ruby-head
     - rvm: jruby-head