[merge from trunk] Use --quiet when running apt-get

ChangeLog

@@ -2,6 +2,7 @@
  - Huge refactor [Joshua Harlow]
 0.6.4:
  - support relative path in AuthorizedKeysFile (LP: #970071).
+ - make apt-get update run with --quiet (suitable for logging) (LP: #1012613)
 0.6.3:
  - add sample systemd config files [Garrett Holmstrom]
  - add Fedora support [Garrent Holstrom] (LP: #883286)

cloudinit/distros/debian.py

@@ -138,7 +138,7 @@ class Distro(distros.Distro):
         # Or: http://tiny.cc/mh91fw
         e['DEBIAN_FRONTEND'] = 'noninteractive'
         cmd = ['apt-get', '--option', 'Dpkg::Options::=--force-confold',
-               '--assume-yes', command]
+               '--assume-yes', '--quiet', command]
         if args:
             cmd.extend(args)
         # Allow the output of this to flow outwards (ie not be captured)