Squad

This release has no functional changes. It just fixes the artifacts published
for the previous release.

* core:
* models.EmailTemplate: add jinja2 syntax validation
* TestComparison: avoid loading too many objects at once.
This fixes a long-running issue with excess RAM usage on workers.
* allow superuser access to all groups, as well as access to empty groups by
group members.
* Refactor project status rebuild command
* frontend:
* add pagination to builds view
* support groups and project with empty name
* prevent displaying 'secrets' from LAVA job definition
* make regressions and fixes popover stay on screen until explicitly closed,
so the data in them can be copied for pasting elsewhere.
* docker
* docker-compose.yaml: add initial version
* celery:
* set maximum number of producer connection attempts
* api:
* Add query result limit to api/data

* Add management command to update project statues from scratch.
* travis:
* fix detection of Javascript test failures
* fix capture of exit status
* Fix a few javascripting
* config.js: removed 'content-type' configuration
* Add import to appConfig for compare.js
* Fix broken charts tests
* Refactor ng apps
* squad/_threshold_table.jinja2: restrict admin controls
* squad/_threshold_table.jinja2: give more specific restriction
* Make all ajax requests contain CSRF header
* Refactor angular apps
* Initialize charts with default summary on all environments.
* Error output missing from failed test cases in tests view.
* api: add missing fields to ProjectStatusSerializer
* core/notification.py: turn off escaping for text emails
* docs: add step-by-step on how to set up SQUAD with LAVA
* Fix previous build ordering in project status test comparison.

* Make notification strategy a per-recipient choice.
* api:
* fix URL generated to baseline in DelayedReport
* fix report caching
* add 'subject' to reports
* frontend: turn Thresholds metrics name into a select control.

* Add community connector files for Google Data Studio data source.
* doc: correct errata in curl example
* api:
* restrict visibility of groups via the API
* Add all test results filtering.
* ci:
* ci/backend/lava.py: fallback `project_settings`

* api:
* fix the /builds/<id>/report API