Add F5 Backup Support

[lykinsbd]

In order to backup F5's we need the following:

• Strategy for handling UCS files and other binaries in Git. Options include Git Annex or Git LFS.
• Write https://github.com/lykinsbd/stockpiler/blob/master/stockpiler/tasks/stockpile/stockpile_f5.py
  • Logic will try the iControl REST API first, then fall back to Netmiko and SSH transport