Add 'ca-certificates' to installed packages.

This is needed to use Debian repos served over https, but also a LOT of
other programs, like reportbug, which want to communicate securely.

Also sorted the list of packages alphabatically as I couldn't find a
reason for the current order and then a logical sort order is better.

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>

raspi_master.yaml

@@ -76,10 +76,11 @@ steps:
 
   - apt: install
     packages:
-    - ssh
-    - parted
+    - ca-certificates
     - dosfstools
     - iw
+    - parted
+    - ssh
     - wpasupplicant
     - __FIRMWARE_PKG__
     - __LINUX_IMAGE__