maintenance release

[chrisbarber]

A bunch of stuff since I haven't merged dev -> release in a long time.

@shus2018, some changes affect deployment:

• Environment installed via conda environment.yml rather than pip requirements.txt; see xrelease PR 24.
• No longer using pipenv for legacy conn routes; see xrelease PR 27 (just remove pipenv install).
• Templatized crossbar config; see xrelease PR 28. There is no longer a usable JSON config checked in; you will need to use ansible or something else to render the template.
• Another major change is addition of a new datacube, defined in datasets-human-mtg.json. I have it disabled when DATACUBE_ENV == 'production' for now.

[shus2018]

Thanks, @chrisbarber I will read through the changes and update deployment. :-)