Include `eslint@7` in peer dependency range

[SimenB]

eslint-plugin-testing-library/package.json

Lines 69 to 71 in f9f499b

	"peerDependencies": {
	"eslint": "^5 || ^6"
	},

[nickserv]

This seems to be a duplicate of #138 and it will be fixed by #139. Mind if I close this?

[SimenB]

Ah, didn't find that somehow when searching 👍

[Belco90]

This has been finally released in v3.9.0 🎉