Update dependency babel-plugin-istanbul to v6 - autoclosed

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
babel-plugin-istanbul	devDependencies	major	5.2.0 -> 6.0.0

---

Release Notes

istanbuljs/babel-plugin-istanbul

### [`v6.0.0`](https://togithub.com/istanbuljs/babel-plugin-istanbul/blob/master/CHANGELOG.md#​600-httpsgithubcomistanbuljsbabel-plugin-istanbulcomparev520v600-2019-12-20) [Compare Source](https://togithub.com/istanbuljs/babel-plugin-istanbul/compare/v5.2.0...v6.0.0) ##### ⚠ BREAKING CHANGES - Drop node.js 6 ([#​226](https://togithub.com/istanbuljs/babel-plugin-istanbul/issues/226)) ##### Features - Add support for instrumenter options ([#​227](https://togithub.com/istanbuljs/babel-plugin-istanbul/issues/227)) ([fe08f5b](https://togithub.com/istanbuljs/babel-plugin-istanbul/commit/fe08f5b8282136c7ed9375fa32148586bd6a7e28)), closes [#​208](https://togithub.com/istanbuljs/babel-plugin-istanbul/issues/208) [#​212](https://togithub.com/istanbuljs/babel-plugin-istanbul/issues/212) - Drop node.js 6 ([#​226](https://togithub.com/istanbuljs/babel-plugin-istanbul/issues/226)) ([93db21a](https://togithub.com/istanbuljs/babel-plugin-istanbul/commit/93db21aa2bbdbb06fb784f52c24a7847fad6be92)), closes [#​209](https://togithub.com/istanbuljs/babel-plugin-istanbul/issues/209)

---

Renovate configuration

:date: Schedule: "every weekend" in timezone America/New_York.

:vertical_traffic_light: Automerge: Disabled by config. Please merge this manually once you are satisfied.

:recycle: Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

:no_bell: Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR has been generated by WhiteSource Renovate. View repository job log here.