Calibre - split RPi from others to use raspbain's testing repo, split off unstable

roles/calibre/defaults/main.yml

@@ -12,5 +12,7 @@ calibre_sample_book: "Metamorphosis-jackson.epub"
 
 calibre_src_url: "https://raw.githubusercontent.com/kovidgoyal/calibre/master/setup/linux-installer.py"
 
-calibre_debs_on_debian: true
 # USE TO TEST debs.yml (RASPBIAN APPROACH!) ON DEBIAN 9.X
+calibre_debs_on_debian: True
+# enable calibre unstable
+calibre_unstable: False

roles/calibre/tasks/debs.yml

@@ -5,13 +5,16 @@
 
 # April 5 2018 raspbian is now tracking the latest Calibre with a small delay.
 # Should you really want the latest just run the below script standalone, it is
-# strongly suggested that waiting for the lastest deb from Rasbian is the best.
+# strongly suggested that waiting for the lastest deb from Raspbian is the best.
 
-- name: Upgrade latest Calibre
+- name: Upgrade to testing Calibre - RPi
+  command: scripts/calibre-install-latest-rpi.sh
+  when: is_rpi
+
+- name: Upgrade to tesing Calibre - non-RPi
   command: scripts/calibre-install-latest.sh
-  #when: not is_rpi
+  when: not is_rpi
 
-# Oops "when: not is_rpi" causes Calibre playbook to fail on Raspbian Lite (possibly
-# other OS's too).  Error msg is: "Unable to start service calibre-serve: Job for
-# calibre-serve.service failed because the control process exited with error code."
-# Running "calibre --version" then responds with "calibre (calibre 2.75.1)".
+- name: Upgrade to unstable Calibre -  all
+  command: scripts/calibre-install-unstable.sh
+  when: calibre_unstable