Remove Quick and Nimble from tests

[JosephDuffy]

This will finally close #181 🙌

Quick is not working on Linux with Swift 5.6 and the watchOS support PRs are too old to be accepted. This will also allow the dependencies to be removed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.05%. Comparing base (506f44a) to head (c28253e).
⚠️ Report is 12 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #258   +/-   ##
=======================================
  Coverage   93.05%   93.05%           
=======================================
  Files           6        6           
  Lines         216      216           
=======================================
  Hits          201      201           
  Misses         15       15           

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