Add docs and requirements to manifest.
Add clean_source command to setup.py
Allow for scalar keys prior to the mosaic axis.
Merge pull request #113 from rhattersley/fix-mosaic-indexing

Allow for scalar keys prior to the mosaic axis.
Merge pull request #88 from rhattersley/clean-source

Add clean_source command to setup.py
Fix tests for Python 3
Merge pull request #100 from rhattersley/manifest

Add docs and requirements to manifest.