Move teuthology.report import; add large warning

Because of the monkey patching, if we get the import order wrong bad
things happen.

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Store the job_id as a str, not an int.

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>