Add exploit for CVE-2014-6034

This is an exploit for a file upload vulnerability in ManageEngine OpManager and Social IT Plus. I've added the link to my advisory in my repo, and I will push a new commit here once the numbers from OSVDB and the full disclosure URL appear in their respective pages.

This module has been very well tested in both Windows and Linux, with almost all versions from 8.8 to 11.3 (the latest). Let me know if you have any questions or if there is anything you want me to change.
``while not session_created?``` seems very forceful. I highly recommend you to set an attempt limit. After a number a tries, it should bail.