Added retry to update operation

manifests/init.pp

@@ -32,6 +32,7 @@ class apt(
   $purge_preferences    = false,
   $purge_preferences_d  = false,
   $update_timeout       = undef,
+  $update_tries         = undef,
   $sources              = undef
 ) {
 

manifests/update.pp

@@ -6,5 +6,7 @@ class apt::update {
     logoutput   => 'on_failure',
     refreshonly => true,
     timeout     => $apt::update_timeout,
+    tries       => $apt::update_tries,
+    try_sleep   => 1
   }
 }