Allow publishing without testing

[ghengeveld]

Some folks like to publish their Storybook without running any tests or taking any snapshots, but only for certain builds or certain branches. This will of course make the build useless for baseline traversal, but that might be okay. For example, a deployment branch such as "staging" doesn't have to be tested (it's already tested on the base branch) but should still be published.

This could be implemented as a --publish-only flag, or using a combination of --no-ui-tests and --no-ui-review (which would disable their respective feature).

Requested in Intercom.

[jordan-cutler]

Hi Chromatic team, any update on this?

[ghengeveld]

@lehighjcut A request through Intercom would help get this prioritized. cc @byebrianwong