added -y flag to apt-get calls

README.rst

 ``apt.dist_upgrade``
 --------------------
 
-Runs ``apt-get dist-upgrade``.
+Runs ``apt-get -y dist-upgrade``.
 
 ``apt.update``
 --------------
 
-Runs ``apt-get update``.
+Runs ``apt-get -y update``.
 
 ``apt.upgrade``
 ---------------
 
-Runs ``apt-get upgrade``.
+Runs ``apt-get -y upgrade``.
 
 ``apt.repositories``
 --------------------

apt/dist_upgrade.sls

-apt-get dist-upgrade:
+apt-get -y dist-upgrade:
   cmd.wait:
     - watch:
       - file: /etc/apt/sources.list

apt/update.sls

-apt-get update:
+apt-get -y update:
   cmd.wait:
     - watch:
       - file: /etc/apt/sources.list

apt/upgrade.sls

-apt-get upgrade:
+apt-get -y upgrade:
   cmd.wait:
     - watch:
       - file: /etc/apt/sources.list