Update nyc to the latest version 🚀

[greenkeeper[bot]]

The devDependency nyc was updated from 14.1.1 to 15.0.0.

This version is not covered by your current version range.

If you don’t accept this pull request, your project will work just like it did before. However, you might be missing out on a bunch of new features, fixes and/or performance improvements from the dependency update.

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Publisher: coreyfarrell License: ISC

Find out more about this release.

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FAQ and help

There is a collection of [frequently asked questions](https://greenkeeper.io/faq.html). If those don’t help, you can always [ask the humans behind Greenkeeper](https://github.com/greenkeeperio/greenkeeper/issues/new).

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Your Greenkeeper bot :palm_tree:

[claassistantio]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[coveralls]

Pull Request Test Coverage Report for Build 1014

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 1000:	0.0%
Covered Lines:	532
Relevant Lines:	532

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💛 - Coveralls

[codecov[bot]]

Codecov Report

Merging #156 into master will not change coverage. The diff coverage is n/a.

@@          Coverage Diff          @@
##           master   #156   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           7      7           
  Lines         266    266           
=====================================
  Hits          266    266

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Continue to review full report at Codecov.

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