.travis.yml in mongoid-archivable-1.7.0 vs .travis.yml in mongoid-archivable-1.7.1

- old
+ new

@@ -11,5 +11,14 @@
     recipients:
       - joost@spacebabies.nl
       - tomas.celizna@gmail.com
     on_failure: change
     on_success: never
+
+matrix:
+  include:
+    - rvm: 2.3.3
+      env: MONGOID_VERSION=5
+    - rvm: 2.3.3
+      env: MONGOID_VERSION=6
+    - rvm: 2.5.0
+      env: MONGOID_VERSION=7