Add tests for EigerHandler and EigerConfigHandler

[jsouter]

Closes (#45)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.06%. Comparing base (3e1482b) to head (3571281).
Report is 3 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #53       +/-   ##
===========================================
+ Coverage   72.20%   84.06%   +11.86%     
===========================================
  Files           4        4               
  Lines         295      295               
===========================================
+ Hits          213      248       +35     
+ Misses         82       47       -35     

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[GDYendell]

Just a few comments.

I think it might be a good idea to intentionally strip down the mock connection here to what we actually use. Or maybe just a MagicMock with specific responses in each test. We do have the system tests for running the introspection against the tickit sim to test the full api.

[GDYendell]

The new unit tests look good 👍