Use Makefile to install requirements and run tests
Useful repr for xblock state
Merge pull request #22 from edx/pmitros/useful-repr

Useful repr for xblock state
Merge pull request #19 from edx/will/makefile

Use Makefile to install requirements and run tests
Pyfilesystem support

Also:
* Some pep8/pylint cleanups
* Latest XBlock update
Removed failing test case for PR merge.
Killed accidental addition