Give tarsnap root-relative paths
(No more "Removing leading '/' from member names" warnings)
Ignore ufw error resulting from known bug on Debian 7

In order to check the version of the linux distribution we need to
set `gather_facts` to True.

Closes #73.
workaround ufw bug, call ufw enable twice
Merge pull request #76 from ariddell/feature/ufw-error-fix

Ignore ufw error resulting from known bug on Debian 7
added SHA check for tarsnap
Merge pull request #78 from pdebruic/master

added SHA check for tarsnap
Add instruction for generating dovecot password_hash
Reworked ufw logic to not use change_when keyword
because it's not available in a stable ansible release yet
Add self-signed cert and default vars to make sovereign testable
Vagrant build and basic tests via Travis CI