Adds apt-get clean

coriolis/osmorphing/debian.py

@@ -35,8 +35,9 @@ class DebianMorphingTools(base.BaseLinuxOSMorphingTools):
 
     def pre_packages_install(self):
         super(DebianMorphingTools, self).pre_packages_install()
-        apt_get_cmd = 'apt-get update -y'
-        self._exec_cmd_chroot(apt_get_cmd)
+        self._event_manager.progress_update("Updating packages list")
+        self._exec_cmd_chroot('apt-get clean')
+        self._exec_cmd_chroot('apt-get update -y')
 
     def install_packages(self, package_names):
         apt_get_cmd = 'apt-get install %s -y' % " ".join(package_names)