fix: update dependencies and tsconfig to support Node 6

[nolanmar511]

No description provided.

[JustinBeckwith]

Usually we just rely on the version in the tsconfig, which as of today in gts@0.9.0 is es2015. When you upgrade to gts@1.0.0, it's gonna bump to es2016 by design. Why hard code it?

[codecov]

Codecov Report

Merging #466 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #466   +/-   ##
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  Coverage   75.94%   75.94%           
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  Files           4        4           
  Lines         212      212           
  Branches       24       24           
=======================================
  Hits          161      161           
  Misses         48       48           
  Partials        3        3

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[nolanmar511]

Clarified the title.
We have continuous integration tests which use Node 6, and those are failing.
I want to get those tests passing, the go through a more conscious effort to drop support for Node 6.

[nolanmar511]

Closing this.

It's probably just too hard to support Node 6, and Node 6 is basically end of life anyways.

[nolanmar511]

Actually, want to get this change in.
It will give time for a more graceful wrap-up of Node 6 support.