fix(deps): update dependency commander to v6

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
commander	dependencies	major	5.1.0 -> 6.0.0

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Release Notes

tj/commander.js

### [`v6.0.0`](https://togithub.com/tj/commander.js/blob/master/CHANGELOG.md#​600-2020-07-21) [Compare Source](https://togithub.com/tj/commander.js/compare/v5.1.0...v6.0.0) ##### Added - add support for variadic options ([#​1250]) - allow options to be added with just a short flag ([#​1256]) - _Breaking_ the option property has same case as flag. e.g. flag `-n` accessed as `opts().n` (previously uppercase) - _Breaking_ throw an error if there might be a clash between option name and a Command property, with advice on how to resolve ([#​1275]) ##### Fixed - Options which contain -no- in the middle of the option flag should not be treated as negatable. ([#​1301])

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