Removes js maps in assets clobber task (#110)

Author: PedroAugustoRamalhoDuarte

lib/tasks/jsbundling/clobber.rake

@@ -1,7 +1,7 @@
 namespace :javascript do
   desc "Remove JavaScript builds"
   task :clobber do
-    rm_rf Dir["app/assets/builds/[^.]*.js"], verbose: false
+    rm_rf Dir["app/assets/builds/[^.]*.{js,js.map}"], verbose: false
   end
 end