Update sprockets to version 3.0.2

Author: sferik

Diff for: Gemfile.lock

@@ -80,7 +80,6 @@ GEM
       activesupport (>= 4.1.0)
     haml (4.0.6)
       tilt
-    hike (1.2.3)
     http-cookie (1.0.2)
       domain_name (~> 0.5)
     http_accept_language (2.0.5)
@@ -201,11 +200,8 @@ GEM
       activesupport (>= 3.0.0)
     slop (3.6.0)
     spring (1.3.4)
-    sprockets (2.12.3)
-      hike (~> 1.2)
-      multi_json (~> 1.0)
+    sprockets (3.0.2)
       rack (~> 1.0)
-      tilt (~> 1.1, != 1.3.0)
     sprockets-rails (2.2.4)
       actionpack (>= 3.0)
       activesupport (>= 3.0)