Fix broken bitly link in help

[rly]

Fix #164

I assume the broken link which points to https://github.com/codecov/support/wiki/Report-Fixes should be replaced with https://docs.codecov.io/docs/fixing-reports

[thomasrockhu]

Thanks @rly! Will merge this pending tests passing (I don't see why in the world they wouldn't)

[codecov]

Codecov Report

Merging #218 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master   #218   +/-   ##
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  Coverage       0%     0%           
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  Files           1      1           
  Lines           1      1           
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  Misses          1      1