Support boolean type for `key`, `endkey`, and `startkey` in view requests

[mojito317]

Checklist

• [x] Tick to sign-off your agreement to the Developer Certificate of Origin (DCO) 1.1
• [x] Added tests for code changes or test/build only changes
• [x] Updated the change log file (CHANGES.md) or test/build only changes
• [x] Completed the PR template below:

Description

Fixes #494

Approach

Allow bool type for endkey, key, and startkey.

Schema & API Changes

• No change

Security and Privacy

• No change

Testing

Edited the invalid tests to use {'foo': 'bar'} invalid values instead of booleans, and extended the existing tests to validate boolean types.

Monitoring and Logging

• No change

[mojito317]

There's a couple of invalid tests that should be removed since boolean type is valid. For example: https://github.com/cloudant/python-cloudant/blob/master/tests/unit/param_translation_tests.py#L298 and https://github.com/cloudant/python-cloudant/blob/master/tests/unit/param_translation_tests.py#L243

We'll also want to modify existing tests to validate boolean types.

I fixed the tests in e876a39 then I realized there is a need for a modification in the code to pass the tests: d89eba6.

[mojito317]

As @ricellis and I agreed offline I put back the invalid tests with {'foo': 'bar'} values that have to be invalid in e76f903.

[mojito317]

Thank you for the review @emlaver and @ricellis! I'm merging this!