Added update to travis
Don't test RDKit on travis because of missing conda packages.
Fix cStringIO py3K issue
Fix cStringIO py3K issue, added six.py
Added another py3k fix, removed import string
Added another py3k fix, replace reset() with seek(0)
Fixed two more py3k issues.
Fixed docstring in create ffxml file
Merge pull request #44 from choderalab/testtravis

[WIP] Added update to travis