Bug 1285539 - Fix 'manage.py check --deploy' on Travis
Bug 1285539 - Fix 'manage.py check --deploy' on Travis

The `manage.py check --deploy` command causes the Django models to be
initialised, which requires Elasticsearch to be accessible, if
`ELASTICSEARCH_URL` is set. The variable is set globally for the Travis
runs, however for the linters job (which is where `check --deploy` was
previously being run) Elasticsearch isn't actually installed.

Whilst we could have just unset `ELASTICSEARCH_URL` for the linters job,
it's best to move the test to the main Python job chunk, since:
* The command doesn't only hit Elasticsearch, but also the DB, and the
linters job is running the older mysql 5.5, rather than mysql 5.6.
* Whilst Elasticsearch isn't currently enabled for anywhere other than
the prototype Heroku instance, we'll soon be using it everywhere, so
should get `check --deploy` to actually test what we plan to deploy.

Note: The exception during `check --deploy` was not turning the Travis
run red, due to `check --deploy` being piped to awk. When we update to
Django 1.10 the awk workaround can be removed, however in the meantime
we can use the bash `pipefail` option to ensure the exit code from the
`manage.py` command propagates through to the one that Travis sees.

glenn124f/treeherder,kapy2010/treeherder,akhileshpillai/treeherder,tojon/treeherder,tojonmz/treeherder,KWierso/treeherder,edmorley/treeherder,glenn124f/treeherder,tojonmz/treeherder,tojonmz/treeherder,kapy2010/treeherder,tojon/treeherder,glenn124f/treeherder,tojonmz/treeherder,kapy2010/treeherder,KWierso/treeherder,tojon/treeherder,akhileshpillai/treeherder,edmorley/treeherder,glenn124f/treeherder,akhileshpillai/treeherder,KWierso/treeherder,tojonmz/treeherder,tojon/treeherder,akhileshpillai/treeherder,kapy2010/treeherder,akhileshpillai/treeherder,glenn124f/treeherder,edmorley/treeherder,tojonmz/treeherder,edmorley/treeherder,glenn124f/treeherder,akhileshpillai/treeherder,KWierso/treeherder,kapy2010/treeherder