FIX: Load post revisions in correct order

app/models/post_revision.rb

@@ -4,6 +4,8 @@ class PostRevision < ActiveRecord::Base
   belongs_to :post
   belongs_to :user
 
+  default_scope { order('number ASC') }
+
   serialize :modifications, Hash
 
   after_create :create_notification

spec/services/username_changer_spec.rb

@@ -224,8 +224,6 @@ describe UsernameChanger do
         end
 
         it 'replaces mentions within revisions' do
-          skip("Erratically fails here raw is nil")
-
           revisions = [{ raw: "Hello Foo" }, { title: "new topic title" }, { raw: "Hello @foo!" }, { raw: "Hello @foo!!" }]
           post = create_post_and_change_username(raw: "Hello @foo", revisions: revisions)
 
@@ -234,7 +232,6 @@ describe UsernameChanger do
 
           expect(post.revisions.count).to eq(4)
 
-          # fails here sometimes with raw is nil
           expect(post.revisions[0].modifications["raw"][0]).to eq("Hello @bar")
           expect(post.revisions[0].modifications["raw"][1]).to eq("Hello Foo")
           expect(post.revisions[0].modifications["cooked"][0]).to eq(%Q(<p>Hello <a class="mention" href="/u/bar">@bar</a></p>))