Add support for AFS deployment

[ttpcodes]

This PR updates deploy.sh so that it is possible to deploy over AFS and avoid using SSH.

If the script detects aklog, it will assume that AFS is installed and authenticate with kinit to get a Kerberos ticket, authenticate to the SIPB cell, and use rsync to deploy CourseRoad. If not installed, this script should default back to SSH for deployment.

[npfoss]

On my system which aklog says aklog not found, yet I got the following printout when I ran the script:

Checking for AFS on this system
AFS detected, using AFS for deployment
Using kdo
./deploy.sh: 27: kdo: not found

Also, I think there's definitely some code duplication that could be avoided here... maybe making the production question separate and "no" just exiting, then doing the setup that's the same for both, then a ternary statement or something for the two lines which are different?

[npfoss]

Update from the meeting: we're starting to think maybe this is adding an unnecessary amount of added complexity for two fairly specific use cases. Discuss?