Update babel-plugin-istanbul to version 4.0.0 🚀

[greenkeeperio-bot]

Hello lovely humans,

babel-plugin-istanbul just published its new version 4.0.0.

State	Update 🚀
Dependency	babel-plugin-istanbul
New version	4.0.0
Type	devDependency

This version is not covered by your current version range.

Without accepting this pull request your project will work just like it did before. There might be a bunch of new features, fixes and perf improvements that the maintainers worked on for you though.

I recommend you look into these changes and try to get onto the latest version of babel-plugin-istanbul.
Given that you have a decent test suite, a passing build is a strong indicator that you can take advantage of these changes by merging the proposed change into your project. Otherwise this branch is a great starting point for you to work on the update.

Do you have any ideas how I could improve these pull requests? Did I report anything you think isn’t right?
Are you unsure about how things are supposed to work?

There is a collection of frequently asked questions and while I’m just a bot, there is a group of people who are happy to teach me new things. Let them know.

Good luck with your project ✨

You rock!

🌴

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The new version differs by 6 commits .

• ac8abab chore(release): 4.0.0
• e902924 fix: load configuration from process.env.NYC_CONFIG if present (#93)
• f77db2a feat: we can now use the language feature Object.assign (#92)
• 80afed9 docs(readme): add Greenkeeper badge 🌴 (#89)
• 594c03a feat: drop Node 0.10 and 0.12 support, upgrade dependencies to reflect this (#88)
• f0b8d7e chore(package): update test-exclude to version 4.0.0 (#86)

See the full diff.

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[codecov-io]

Codecov Report

Merging #680 into master will not change coverage.

@@           Coverage Diff           @@
##           master     #680   +/-   ##
=======================================
  Coverage   92.28%   92.28%           
=======================================
  Files         180      180           
  Lines        1996     1996           
=======================================
  Hits         1842     1842           
  Misses        154      154

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