Modularize, 100% coverage, optimizations and more logs

[pvdlg]

Reorganize the code to make testable modules and unit test for 100% coverage. Overall the module should be easier to troubleshoot, more efficient (fails faster in case of failed job) and a lot more gentle on the Travis API.

Optimizations:

• Call builds endpoint once per attempt rather than calling jobs for each job and each attempt
• Implement an exponential backoff strategy for a gentler API usage
• Fail as soon a job fails even if a previous in the list if pending
• Do not call the API on the first attempt as the jobs are already retrieved to determine the build leader

Fixes:

• Return false if the current job test have failed rather than the 'Not running in Travis after_success step' error

Fix #11

[codecov[bot]]

Codecov Report

Merging #14 into master will increase coverage by 82.53%. The diff coverage is 100%.

@@            Coverage Diff            @@
##           master    #14       +/-   ##
=========================================
+ Coverage   17.46%   100%   +82.53%     
=========================================
  Files           3      8        +5     
  Lines          63    105       +42     
=========================================
+ Hits           11    105       +94     
+ Misses         52      0       -52

Impacted Files	Coverage Δ
lib/elect-build-leader.js	100% <100%> (ø)
lib/get-logger.js	100% <100%> (ø)
lib/verify-jobs-state.js	100% <100%> (ø)
lib/validate.js	100% <100%> (ø)
lib/get-jobs.js	100% <100%> (ø)
lib/travis-deploy-once.js	100% <100%> (ø)
lib/wait-for-other-jobs.js	100% <100%> (ø)
lib/get-client.js	100% <100%> (ø)
... and 6 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update ef41ddc...93ab749. Read the comment docs.