Ensure we reconnect with the same options passed to start

[CharlieHess]

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• I've read and agree to the Code of Conduct.
• I've been mindful about doing atomic commits, adding documentation to my changes, not refactoring too much.
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PR Summary

This PR handles an issue with the RTM client wherein reconnects do not use the same arguments originally given to rtm.start. So, if you specify something like simple_latest, it'll work the first time, but reset to default once you reconnect.

Related Issues

There was no issue filed for this bug. This PR fixes an unrelated issue with the README, see #300.

Test strategy

I added a test that reproduces this case.

[codecov]

Codecov Report

Merging #347 into master will increase coverage by 0.18%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #347      +/-   ##
==========================================
+ Coverage    85.8%   85.99%   +0.18%     
==========================================
  Files          44       44              
  Lines        1205     1207       +2     
  Branches      178      178              
==========================================
+ Hits         1034     1038       +4     
+ Misses        171      169       -2

Impacted Files	Coverage Δ
lib/clients/rtm/client.js	72.79% <100%> (+0.94%)	⬆️

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[aoberoi]

you are a saint for fixing things like this 🙏

[CharlieHess]

i gotchu dawg

[aoberoi]

this is awesome!