Fix push/merge access level models.

The models were incorrectly merged (this would have been avoided if !927
was merged in, but that MR is still review) leading to a few spec failures.

app/models/protected_branch/merge_access_level.rb

@@ -16,4 +16,12 @@ class ProtectedBranch::MergeAccessLevel < ActiveRecord::Base
       Gitlab::Access::DEVELOPER => "Developers + Masters"
     }.with_indifferent_access
   end
+
+  def check_access(user)
+    return true if user.is_admin?
+    return user.id == self.user_id if self.user.present?
+    return group.users.exists?(user.id) if self.group.present?
+
+    super
+  end
 end

app/models/protected_branch/push_access_level.rb

@@ -21,6 +21,7 @@ class ProtectedBranch::PushAccessLevel < ActiveRecord::Base
 
   def check_access(user)
     return false if access_level == Gitlab::Access::NO_ACCESS
+    return true if user.is_admin?
     return user.id == self.user_id if self.user.present?
     return group.users.exists?(user.id) if self.group.present?