Add configurability and JIRA version creation/release

Added a bit of configurability to make it easier to test the bot on a different network or in a different channel. Also added two methods for working with versions on JIRA. createVersion allows a valid user to create a version in JIRA, releaseVersion allows a valid user to mark an existing version as released.
Is there any need to rename <code>channel</code> to <code>chan</code>? It prevents conflicts with class fields, but it causes many changes unrelated to the PR