* First cut of supporting quantiles ("percent ranks") per allele. Closes #87.
* Some refactoring of amino_acid.py

This builds on #114

Implement BLOSUM62 encoding

* Switch from JSON to YAML for hyperparameters
* Pin tensorflow (hoping will help with #110)

Fixing code typo: allelle -> allele.

update setup.py

Remove versioneer

Set up versioneer