Update dependency prettier to v2

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
prettier (source)	devDependencies	major	1.19.1 -> 2.0.0

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Release Notes

prettier/prettier

### [`v2.0.0`](https://togithub.com/prettier/prettier/blob/master/CHANGELOG.md#​200) [Compare Source](https://togithub.com/prettier/prettier/compare/1.19.1...2.0.0) [diff](https://togithub.com/prettier/prettier/compare/1.19.1...2.0.0) 🔗 [Release Notes](https://prettier.io/blog/2020/03/21/2.0.0.html)

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