Use job ID instead of mailing ID as the head of mailjet custom campaign
ID.
Fixed the timestamp of test mailing.
Changed the created_date parameter to scheduled_date.
Clean up all the possible invalid variables.
Put identify test on a higher level.
Merge pull request #5 from popcm/development

Remove all the test mailings from bulk mailing campaign.
Fixed the issue that when one email address got deleted when put on hold.
Added detail comments for future debugging.
Merge remote-tracking branch 'guanhuan/development' into release-1.01
Fixed the bounce fetch from Mailjet.
Bounce now will be recorded to contact correctly and the email address will not get deleted