sync_folder is an absolute path #22
Description
sync_folder is currently an absolute path, which prevents (ironically) syncing the PackageSyncing settings between different machines.
For example, if my home directory is /home/usera and /home/userb on two different machines, and I copy my Sublime .config/sublime-text-3/Packages/User/ settings between the two machines (which includes the Package Syncing plugin), I run into issues.
Suggested Remedy: Run os.path.expanduser or os.path.expandvars on sync_folder.
Alternately, prefix the home directory to the path if it does not start with a / or \ (i.e., is a relative path).