Upgrade to React16

[SebastienGllmt]

Fairly standard upgrade.

All tests, etc. pass

[codecov-io]

Codecov Report

Merging #125 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #125   +/-   ##
=======================================
  Coverage   96.77%   96.77%           
=======================================
  Files           2        2           
  Lines          31       31           
  Branches        7        7           
=======================================
  Hits           30       30           
  Misses          1        1

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[SebastienGllmt]

Any chance this gets accepted? React-intl will be upgraded to 3.0.0 at some point which will depend on React 16 hooks