feat(services): add heroku CI

[sy-hash]

Port codecov/codecov-ruby#28 to node.

[codecov]

Codecov Report

Merging #127 into master will increase coverage by 0.2%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master     #127     +/-   ##
=========================================
+ Coverage   88.95%   89.16%   +0.2%     
=========================================
  Files          19       20      +1     
  Lines         317      323      +6     
  Branches       80       80             
=========================================
+ Hits          282      288      +6     
  Misses         35       35

Impacted Files	Coverage Δ
lib/detect.js	92.3% <ø> (ø)	⬆️
lib/services/heroku.js	100% <100%> (ø)

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[sy-hash]

@eddiemoore Could you please review?

[sy-hash]

Thank you for reviewing and publishing!