Move tarsnap.key from /root to /decrypted and don't overwrite it if one already exists (fixes #15)

roles/tarsnap/files/tarsnaprc

-keyfile /root/tarsnap.key
+keyfile /decrypted/tarsnap.key
 cachedir /usr/tarsnap-cache
 exclude /usr/tarsnap-cache
 humanize-numbers
-

roles/tarsnap/tasks/tarsnap.yml

     dest="/root/tarsnap-autoconf-{{ tarsnap_version }}.tgz"
     sha256sum={{ tarsnap_sha.stdout_lines[0] }}
 
-
 - name: Decompress Tarsnap source
   command: tar xzf /root/tarsnap-autoconf-{{ tarsnap_version }}.tgz chdir=/root creates=/root/tarsnap-autoconf-{{ tarsnap_version }}/COPYING
 
   command: make all install clean chdir=/root/tarsnap-autoconf-{{ tarsnap_version }} creates=/usr/local/bin/tarsnap
 
 - name: Copy Tarsnap key file into place
-  copy: src=root_tarsnap.key dest=/root/tarsnap.key owner=root group=root
+  copy: src=decrypted_tarsnap.key dest=/decrypted/tarsnap.key owner=root group=root force=no
 
 - name: Create Tarsnap cache directory
   file: state=directory path=/usr/tarsnap-cache