refs #79: Updated travis to test on 3.3
refs #79: Fixed print statements.
refs #79: All but images working.
refs #79: Fixed some broken tests for python 2.
refs #79: Got python3 passing, still a few small problems with python2
refs #79: Experimental support for python 3.4
Revert "refs #79: Experimental support for python 3.4"

This reverts commit 9b49d0058d8ad01bb86f36b29e7642fde92ddec9.
refs #79: Got the last of the tests passing in both python2 and python3
refs #79: Updated a test.
refs #79: Removed legacy test code.
refs #79: Docstring.
refs #79: Actually fixed the performance test.
refs #79: Added doc tests.
refs #79: Update note. Updated trove classifiers.
refs #79: Updated the other performance test.
Merge pull request #79 from CenterForOpenScience/issue_79

Python 3 support