Exports `notifyWithSlack` for those using the CLI within their own CI

[Alastair-Spencer]

Description

Whilst the Github App is having issues sending notifications, we have written our own CLI wrapper to handle this within our Concourse pipelines. We would like to make use of notifyWithSlack directly.

Type of change

Please delete options that are not relevant.

• [x] New feature (non-breaking change which adds functionality)

Checklist:

• [x] I have followed the CONTRIBUTING doc and the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules

[Alastair-Spencer]

@kamilkisiela Please may I have a review on this? We're hoping to use this soon 🤞🏻

Thank you 😃

[TuvalSimha]

@Alastair-Spencer Hey :)

Still needed?

[Alastair-Spencer]

Hey @TuvalSimha - Sorry I missed your message. Yes please!

[Alastair-Spencer]

We're currently using patch-package with the above fix in order to get around this issue