Support for pushing notifications to JIRA on a deploy

This is one half of the changes needed to support OPS-177 - pushing
updates to JIRA on a prod deploy.  (The other half will be modifying the
web repo to use what's in this commit).

Testing Done:

* bundle exec rspec spec/jira_spec.rb - OK
* bundle exec rspec - OK
* (in a modified web repo) cap preview email:notify_jira - OK