Add docs and testing + ci, code cov, black

[lwasser]

This should enable make docs -B to work properly. it's hard to run make when there is no makefile as it turns out :)

This also

1. runs black on all modules
2. adds titles to all modules for autodoc to work
3. cleans up a few spacing issues that was blocking autodoc from working properly
4. implements travis running make docs to align with local testing

[lwasser]

this PR turned into a monster. it's close

============================ no tests ran in 0.10s =============================

ERROR: InvocationError for command /home/travis/build/earthlab/abc-classroom/.tox/py36/bin/pytest -v --basetemp=/home/travis/build/earthlab/abc-classroom/.tox/py36/tmp --cov=abcclassroom (exited with code 5)

___________________________________ summary ____________________________________

ERROR:   py36: commands failed

The command "./.travis/test.sh" exited with 1.

these commands run locally so something is not configured correctly in travis. i'm not sure if this is related to the web hook not connecting properly or something else...

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@f0af938). Click here to learn what that means.
The diff coverage is 50%.

@@          Coverage Diff           @@
##             master   #68   +/-   ##
======================================
  Coverage          ?   50%           
======================================
  Files             ?     2           
  Lines             ?    26           
  Branches          ?     0           
======================================
  Hits              ?    13           
  Misses            ?    13           
  Partials          ?     0

Impacted Files	Coverage Δ
abcclassroom/distribute.py	35% <0%> (ø)
abcclassroom/tests/test_distribute.py	100% <100%> (ø)

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