Upgrade to ESLint 7

[LinusU]

ref: #1518

Blocked on:

• [New] support eslint v7 jsx-eslint/eslint-plugin-react#2635
• Update to rules moved out from ESLint 7 eslint-config-standard#169
• Add new rules from ESLint 7.0.0 eslint-config-standard#170

Tests blocked on:

• Add eslint-disable comment to WebTorrent.chromeapp.js webtorrent/webtorrent#1856
• style: remove unnecessary parentheses around expression webtorrent/parse-torrent#85

Todo:

• https://github.com/standard/eslint-config-standard/issues/171
• Upgrade to eslint-config-standard 15.0.0
• Upgrade to eslint-plugin-react 7.20.0

[Raynos]

I reviewed all related PRs.

3 have merged and two have been approved.

[sheerun]

oh man, can't wait :)

[Raynos]

I’m not comfortable merging these PRs as is.

Would it be ok to create a temporary git repo standard7 and eslint-config-standard7 ?

I can merge all these PRs in there and then publish new npm packages standard7 / eslint-config-standard7 .

The community can play with these packages and once all the bugs are worked out everything can be merged into standard version 15

Cc @LinusU @feross @voxpelli

[voxpelli]

I would suggest we merge them all to a 15.x branch and publish a 15.x prerelease from that branch instead

[feross]

I'm working on this today.

[feross]

LGTM