The following plists and scripts are used on VOKAL's iOS build server. Thanks to the magic of launchd the backup script runs once a day and the dropoff script runs as needed. The dropoff script imports p12 files to the system keychain and moves provisioning files to correct folder.
To use these scripts put them somewhere safe, then put the plist files in /Library/LaunchDaemons Update the paths to the scripts, fix the ACCESS_KEY_ID and SECRET_ACCESS_KEY variables, and you're on your way.
If you have questions about Daemons and Agents look at Apple's technote: https://developer.apple.com/library/mac/technotes/tn2083/_index.html
UPDATE: I've found WatchPaths works intermittently. I'm not sure why.