Initial testing for parallelization
move override of MODULESTORE settings into ModuleStore test case class
Added the beginnings of self cleanup
Contentstore singleton is now cleared during teardown
Moved port range to rake file
Cleaned up import and comment
Fixed pylint/pep8 violations
Consolidated imports
Test Mongo database is now unique and destroyed in teardown
Merge pull request #220 from edx/jonahstanley/make-units-parallel

Jonahstanley/make units parallel