GitLab

Create review EC2 instances in a private subnet and use *private.review.technicie.nl instead of *.reviewhost.

This reverts merge request !1429

Adds a new stage to the gitlab CI which pushes the coverage html report
to coverage.technicie.nl using the sftp command

Otherwise we delay our pipelines.

Don't test Django 2.1 yet as that fails

For tags, we'll also push and tag that container.

Use `sphinx-build -j` and `nproc` to distribute collecting and compiling
the documentation over all cores.

Further improve documentation

Include docs for utils submodules

docs build needs the dev requirements as it will import commands

Further improve docs

Surpresses a warning and we haven't had issues with the binary package

See also http://initd.org/psycopg/docs/install.html#binary-install-from-pypi