Allow JIRA service to use email or API token instead of username for authentication
JIRA service started to deprecate the use of usernames on jun-2018: https://confluence.atlassian.com/cloud/blog/2018/06/say-goodbye-to-usernames-in-atlassian-cloud
The username field is already hidden in JIRA cloud control panel which affects new users integrating it with GitLab. We should update our docs and change our integration to use jira account email address or API token and alert our users of this change somehow.
The current gem used in our JIRA service is https://github.com/sumoheavy/jira-ruby which seems to support API TOKEN and OAUTH:
- Use email / API token
- Also update the UI labels for the inputs