Clkhash

Removes `rest_client` and `cli` modules. This functionality has
been migrated to [anonlink-client](https://github.com/data61/anonlink-client/).

Breaking Changes
- clkhash continues its metamorphosis from a client to a support library. Clkhash now returns the computed CLKs as bitarrays and not as base64-serialized strings any more. (370)

- Fixes bug validating linkage schemas with ignored fields. 342
- Added warnings about upcoming removal of `rest_client` and `cli`. This functionality has
been migrated to [anonlink-client](https://github.com/data61/anonlink-client/)
- Update dependencies

- fixed issue where NumericComparison couldn't tokenize empty inputs 323

Introduced linkage schema v3 that permits you to specify different comparison techniques.
The [hashing schema documentation](http://clkhash.readthedocs.io/en/latest/schema.html) provides more details.
There is also a [tutorial](https://clkhash.readthedocs.io/en/stable/tutorial_comparisons.html) describing the different comparions techniques.

- CLI can handle rate limiting from the entity service 277
- introduce hypothesis testing 280
- improvements to Azure CI pipeline 284, 294, 312, 313
- Added ability to define alternative comparison techniques 286
- Exact comparison 290
- improved schema documentation 293
- update rest client 297
- renamed the strategies 302
- Switch to using a fork of `bitarray` that distributes binary wheels. This means installing clkhash no longer
requires a c compiler. 308
- added new command for schema conversion to clkutil 309
- update randomnames schema 311
- addressed warnings in tests 315
- added numeric comparison 316
- remove mapping type from tutorials and cli 317
- tutorial about comparisons 318

Breaking Changes

- The cli method `hash` requires only one secret instead of two. 303
- The clks generated with `clkhash` <= 0.14.0 are not compatible with clks from version 0.15.0 onwards.

- Fix bug where empty inputs don't generate tokens.
- CLI commands to delete runs and projects. 265
- Migrate to Azure DevOps for CI testing. 262
- Synthetic data generation using distributions. 271, 275

- Fix example and test linkage schemas using v2.
- Fix mismatch between double hash and blake hash key requirement.
- Update to use newer anonlink-entity-service api.
- Updates to dependencies.
- Better test coverage
- CI now executes tutorial notebooks
- CI now automatically releases to PyPi