re-add other versions to matrixg

Author: bolandrm

.travis.yml

@@ -9,17 +9,17 @@ before_install:
   - gem install bundler --version '< 2'
 
 gemfile:
+  - gemfiles/sprockets-rails_3_0.gemfile
+  - gemfiles/sprockets-rails_2_3.gemfile
+  - gemfiles/sprockets_3_0.gemfile
+  - gemfiles/sprockets_4_0.gemfile
   - gemfiles/rails_4_2.gemfile
-  #- gemfiles/sprockets-rails_3_0.gemfile
-  #- gemfiles/sprockets-rails_2_3.gemfile
-  #- gemfiles/sprockets_3_0.gemfile
-  #- gemfiles/sprockets_4_0.gemfile
-  #- gemfiles/rails_5_2.gemfile
+  - gemfiles/rails_5_2.gemfile
 
 rvm:
   - 2.4.6
-  #- 2.5.5
-  #- 2.6.3
+  - 2.5.5
+  - 2.6.3
   - jruby
 
 matrix: