cerveja began
given up on python-dialog for now: cerveja now is able to compute a simple grain bill
flake8 suggestions
Hurray! cerveja now calculates grain bills
gravity is a better (and more general) name for a command than grainbill
added to-do list
some extra spacing for -h
__main__ more readable
Merge branch 'release/0.1'
Merge tag '0.1' into develop

First release:

- cerveja is now able to calculate the original gravity for a grain bill.