Simplify Elasticsearch initialization
Add pytest section to setup.cfg

All this does is make it possible to run `py.test` instead of
`python setup.py test`, which is convenient when there is a need to
pass some extra arguments.
Use pyramid.includes in h.script

This ensures that extra modules in the .ini are loaded. In particular,
this ensures that the accounts module has a chance to bind its models.
Otherwise, the SQL tables aren't created.
Add Gemfiles and ruby buildpack

This change makes it possible to build straight-away with a vanilla
dokku buildstep and also on heroku using the multi-buildpack, rather
than requiring compass to be installed separately.
Remove sass version pin

3.4.7 fixed the issue.
Only check ES plugins when creating the index
PEP8
Remove unused imports
Set up logging in h.script
Support Redis to Go Heroku add-on
Zero-downtime deploys on dokku

\o/
Revert "Zero-downtime deploys on dokku"

This reverts commit c428d5914fec2de1612b8d93e384e384a05ab98a.

This isn't going to work in production for us because hitting the
server behind the load-balancer on the localhost URL is going to
generate the wrong URLs in the CSS assets and will fail because
of our use of the PROXY protocol.
Revert "Simplify Elasticsearch initialization"

This reverts commit 68eacf5a5d45f0ece0f184dd5e74909f27daaeab.
Improve Elasticsearch initialization

Improve the way that Elasticsearch is initailized in a couple ways:

- Take the analysis settings from the classes the same way that the
  mappings are taken.

- Merge mappings and analysis into the initial index creation. This
  avoids the need to close and re-open the index for the initial
  analysis settings configuration.

- Re-open the index in a finally clause, to ensure that it is never
  left closed when performing analysis settings updates.

- Detect index already exists error more robustly.