Merge pull request #6 from danielhyduke/master

Updates from oc
Brought in latest updates from opencobra/cobrapy master
Merge branch 'master' into patches
Fixed a bug arising from opencobra/cobrapy pull request 53 where Reaction.get_genes was deprecated.  Added in a unit test to deal with the weird behavior
Merge pull request #8 from danielhyduke/patches

Fixes a bug introduced in https://github.com/opencobra/cobrapy/pull/53