Resolve "`get_event_data` still used in some examples despite being removed as a deprecated function"

- Also applies Black for future inclusion

1) Introduce "nsamples" functionality
2) Improve the evidence estimates
3) Improve result caching and exit behaviour

Colm Talbot authored 5 years ago and Gregory Ashton committed 5 years ago

The dump is written to a temporary file and then the main resume file is
overwritten by a rename.

Gregory Ashton authored 5 years ago and Moritz Huebner committed 5 years ago

1) Restrict the dynamic dynesty test to maxcalls of 100
2) Split the sampler_test out of the main tests and into a separate
node. This means the sampler_test doesn't contribute to the coverage

This adds a test-mode command like argument to run with zero likelihood.
As such, this will sample from the priors alone. To use, run any
standard bilby example with `--bilby-zero-likelihood-mode` in the
command line. This has been intentionally obfuscated to avoid
overloading the usual documentation.

1) Rename all tests to the pytest standard naming convention
2) Update to use pytest to run the tests and collect coverage
3) Simplify gitlab CI script using above changes

Partial solution to #181