Motivation:

During proposal review, and while working within the codebase, several issues were identified with how `RedisConnection` was architectured.

Modifications:

- Change implementation of `RedisConnection` in some areas for new logic of internal `ConnectionState`
- Change behavior of logging in a few places
- The initializer for `RedisConnection` is now **internal**
- How users can override the default `ClientBootstrap` for a connection is by passing an instance to the `.connect` static method
- Change unit tests to inherit from a common XCTestCase class that handles creation and cleanup of `RedisConnection` in tests
- Remove Redis namespace enum

Result:

The API for `RedisConnection` should be much simpler, with the implementation being less buggy.

This resolves issues #49, #54, and #57.