Returns the credentials merged with the config data (opts + pillar).

def _get_credentials(server=None,
                     username=None,
                     password=None):
    '''
    Returns the credentials merged with the config data (opts + pillar).
    '''
    jira_cfg = __salt__['config.merge']('jira', default={})
    if not server:
        server = jira_cfg.get('server')
    if not username:
        username = jira_cfg.get('username')
    if not password:
        password = jira_cfg.get('password')
    return server, username, password