Upgrade Sprockets and Sprockets Rails.

Upgrade Sprockets from 3.6.0 to 3.6.2.

Changelog: https://github.com/rails/sprockets/blob/3.x/CHANGELOG.md

Upgrade Sprockets Rails from 3.0.4 to 3.1.1.

Changelog: https://github.com/rails/sprockets-rails/compare/v3.0.4...v3.1.1

Gemfile.lock

@@ -700,10 +700,10 @@ GEM
       spring (>= 0.9.1)
     spring-commands-teaspoon (0.0.2)
       spring (>= 0.9.1)
-    sprockets (3.6.0)
+    sprockets (3.6.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.0.4)
+    sprockets-rails (3.1.1)
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)