Attempt to remove swap

Attempts to persist the deactivation of swap across reboots.
Note: this can still be overridden by external mechanisms
such as cloud-init

Fixes Bug 1062

Change-Id: I4b78191da63a1528bfe56d2c3e9a33342b86af21
Signed-off-by: beierlm <mark.beierl@canonical.com>