Tooling for debugging adapt

[clusterfudge]

A potentially breaking change (with no identifiable users) is removing
the dependency on pyee. Two events (tagged_entities and parse_results)
will no longer be emitted. There do not appear to be any consumers of
these events in adapt, mycroft-core, or skills.

• Description of what the PR does, such as fixes # {issue number}
  Fixes Tooling for debugging Adapt #129

• Description of how to validate or test this PR
  ./run_tests.sh validates all existing behavior with no changes.
  Additional instrumentation upstream needed to invoke debug utilities.

• Whether you have signed a CLA (Contributor Licensing Agreement)
  Yes

[forslund]

I think this looks good, the Pyee was probably only used in my WIP branch for adding debug-prints for adapt to mycroft-core so should be fine to remove. It'll make the code somewhat easier to follow as well.

Since there is a new pickling protocol in python 3.8 and the world is a bit splitted across 3.6+ versions of python right now do you think the pickling protocol should be locked to 4? to guarantee that all dumps can be opened on all supported python versions?

Edit: default version The default protocol version is 4 in python 3.8+ and 3 in the versions preceding python 3.8 so all versions should be unpicklable no matter which of the supported python versions are used.