Add some unrecoverable errors

[CharlieHess]

Summary

This PR makes sure that user_removed_from_team and team_disabled are marked as unrecoverable errors during an rtm.start or rtm.connect. We were seeing cases in the desktop app wherein a user had been removed from the org but continued to retry the connection.

Requirements (place an x in each [ ])

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

Merging #415 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #415   +/-   ##
=======================================
  Coverage   88.96%   88.96%           
=======================================
  Files          44       44           
  Lines        1241     1241           
  Branches      187      187           
=======================================
  Hits         1104     1104           
  Misses        137      137

Impacted Files	Coverage Δ
lib/clients/rtm/client.js	84.15% <ø> (ø)	⬆️

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