chore(ci): add newer versions of go

[cyberhck]

closes #6

[cyberhck]

have to use string for version number

look into: travis-ci/gimme#132 & travis-ci/gimme#130

wait for pull to merge and 132 to close

[codecov]

Codecov Report

Merging #7 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master     #7   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           1      1           
  Lines         112    112           
=====================================
  Hits          112    112

---

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 418d0c1...5eb0263. Read the comment docs.