Make a copy of the dependencies list 

Make a copy of the dependencies list so that, if the natural_key method is defined on a super class, we don't end up modifying the dependencies for all classes that inherit it.
Merge pull request #10 from MikeAmy/develop

Make a copy of the dependencies list
[requires.io] dependency update
[requires.io] dependency update
Merge pull request #11 from saxix/requires-io-develop

[requires.io] dependency update on develop branch
[requires.io] dependency update
Merge pull request #12 from saxix/requires-io-develop

[requires.io] dependency update on develop branch
django 1.7 compat
minor fixes
bump 0.7
Merge branch 'release/0.7'

* release/0.7:
  bump 0.7
  minor fixes
  django 1.7 compat
  [requires.io] dependency update
  [requires.io] dependency update
  [requires.io] dependency update
  Make a copy of the dependencies list