Pull XML serialization out into a separate mixin [PLAT-229]
Fix script/coverage
Add methods to IdReader and IdGenerator for working with XBlockAside usage ids [PLAT-210]
Make base abstract methods raise NotImplementedError
Ignore common non-coverable lines
Merge pull request #265 from cpennington/fix-coverage-script

Fix script/coverage
Merge pull request #263 from cpennington/separate-xml-serialization-mixin

Pull XML serialization out into a separate mixin [PLAT-229]
Merge pull request #262 from cpennington/xblock-aside-ids

Add methods to IdReader and IdGenerator for working with XBlockAside usage ids [PLAT-210]
Use python-versioneer to prep PyPI pushes
Add a makefile for running tests/packaging
Make travis.yml use the make file