Merge branch 'file_lock_permissions' into 'master'

Users with master permissions cannot edit the file locks

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/702

See merge request !494

app/helpers/path_locks_helper.rb

 module PathLocksHelper
-  def can_unlock?(path_lock, current_user = @current_user)
-    can?(current_user, :admin_locks, path_lock) || path_lock.user == current_user
+  def can_unlock?(path_lock, current_user = @current_user, project = @project)
+    can?(current_user, :admin_path_locks, project) || path_lock.user == current_user
   end
 
   def license_allows_file_locks?

app/models/ability.rb

@@ -301,7 +301,7 @@ class Ability
         :admin_pipeline,
         :admin_environment,
         :admin_deployment,
-        :admin_locks
+        :admin_path_locks
       ]
     end