Finalize merge of pull request #178. [ fixed #177 ]

Author: Ben Atkins

CHANGELOG.md

@@ -1,8 +1,11 @@
 ## 2.6.4 (unreleased)
 
+  - [#177](https://github.com/airblade/paper_trail/issues/177)/[#178](https://github.com/airblade/paper_trail/pull/178) -
+    Factored out `version_key` into it's own method to prevent `ConnectionNotEstablished` error from getting thrown in
+    instances where `has_paper_trail` is declared on class prior to ActiveRecord establishing a connection.
   - [#176](https://github.com/airblade/paper_trail/pull/176) - Force metadata calls for attributes to use current value
     if attribute value is changing.
   - [#173](https://github.com/airblade/paper_trail/pull/173) - Update link to [diff-lcs](https://github.com/halostatue/diff-lcs).
-  - [#172](https://github.com/airblade/paper_trail/pull/172) - Save object_changes on creation.
+  - [#172](https://github.com/airblade/paper_trail/pull/172) - Save `object_changes` on creation.
   - [#167](https://github.com/airblade/paper_trail/pull/167) - Fix `originator` method so that it works with subclasses and STI.
   - [#160](https://github.com/airblade/paper_trail/pull/160) - Fixed failing tests and resolved out of date dependency issues.

lib/paper_trail/has_paper_trail.rb

@@ -76,7 +76,7 @@ def has_paper_trail(options = {})
       end
 
       def version_key
-        return self.version_class_name.constantize.primary_key
+        self.version_class_name.constantize.primary_key
       end
 
       # Switches PaperTrail off for this class.