Add compatible ActiveSupport versions to test matrix

Test against latest ruby

Author: avit

.travis.yml

@@ -12,3 +12,19 @@ rvm:
   - 2.0
   - 2.1
   - 2.2
+  - 2.3
+  - ruby-head
+env:
+  - RAILS_VERSION='~> 3.2'
+  - RAILS_VERSION='~> 4.2'
+  - RAILS_VERSION='~> 5.0'
+matrix:
+  exclude:
+    - rvm: 1.9.3
+      env: RAILS_VERSION='~> 5.0'
+    - rvm: 2.0
+      env: RAILS_VERSION='~> 5.0'
+    - rvm: 2.1
+      env: RAILS_VERSION='~> 5.0'
+    - rvm: 2.2
+      env: RAILS_VERSION='~> 5.0'