Create a JIRA ticket when raising a pull request

[dylanslewis]

If a pull request is going to be raised, then a JIRA ticket should also be raised so that the updated styles can be tested by QA after the pull request has been merged.

The required information to collect from the config file is:

• OAuth token
• Board name
• Initial status (most likely some 'In Review' equivalent)

After creating the ticket, the pull request can then have the ticket reference in the title, rather than [stylesync] (which can still be used as a fallback if the user doesn't want to raise a JIRA ticket.)

This could potentially be done as a separate Swift framework, which just accepts these configuration variables as parameters. The dependancy to that framework can then just be added to Package.swift.