fix(build): do not emit UMD modules

[jdiaz5513]

Closes #86, #85.

[codecov]

Codecov Report

Merging #87 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master     #87   +/-   ##
======================================
  Coverage    80.1%   80.1%           
======================================
  Files          50      50           
  Lines        3202    3202           
  Branches      255     255           
======================================
  Hits         2565    2565           
  Misses        569     569           
  Partials       68      68

---

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 7cd7193...3854de8. Read the comment docs.