Ert

- Use matplotlib's Qt5 backend rather than Qt4

- Add project arg to ert vis launcher

- Add first iteration of ensemble evaluator
- Implement Legacy Ensemble
- Remove trailing whitespace from RST files
- Expand tabs (8 spaces), allowing maintenance of RST table
- Fix RST formatting bugs
- Add hint on refcase and obs_config
- Remove legacy logo
- Remove manual draining of work_queue
- Add tests verifying migration behaviour
- Add pytest timeout to some tests
- Use matplotlib's Qt5 backend rather than Qt4

- Allow MeasuredData to allow loading only observations
- Remove warning using storage on secret data
- Remove the check for either having prior or reference set, to enable DESIGN_KW
- Drop blob DB in favour of single entities DB
- API server SIGTERM when parent process ends
- Start API server in a context manager
- Remove config_help.py
- Add visualization launcher using hook plugin
- Add sub categories to job sections
- Remove upper version limit matplotlib
- Convert DataFrame to ndarray before plotting
- Fix plotting with no cases available
- Fix warning when plotting without any cases
- Add 2.16 release notes
- Minor fixes and corrections to the observation format docs
- Introduce alembic db revisions