Allow disabling -z by compress property

[k0kubun]

When I used hocho on an Arch Linux server, I got:

=> $ rsync -az --copy-links --copy-unsafe-links --delete --exclude\=.git --rsh ssh\ -o\ \"PubkeyAuthentication\=yes\"\ -o\ \"PasswordAuthentication\=yes\"\ -o\ \"PreferredAuthentications\=none,publickey,password,keyboard-interactive\"\ -o\ \"User\=k0kubun\" . chkbuild006.hsbt.org:/tmp/hocho-run-5ybRSjNad/itamae
Enter passphrase for key '/Users/k0kubun/.ssh/id_rsa':
rsync: This rsync lacks old-style --compress due to its external zlib.  Try -zz.
rsync error: syntax or usage error (code 1) at main.c(1578) [server=3.1.3]
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at /BuildRoot/Library/Caches/com.apple.xbs/Sources/rsync/rsync-54/rsync/io.c(453) [sender=2.6.9]

I tried changing -z to -zz as instructed by that, but it didn't work. So I'd like to have a property to just disable compression.

foo.bar:
  properties:
    compress: false