Add option to specify imap folder

manifests/server.pp

@@ -20,6 +20,7 @@ class lpmqtt::server (
   $imap_hostname,
   $imap_password,
   $imap_use_ssl = true,
+  $imap_folder = 'INBOX',
   $mqtt_hostname = 'firehose01.openstack.org',
   $topic = 'launchpad',
   $mqtt_username = 'infra',

templates/lpmqtt.conf.erb

@@ -3,6 +3,7 @@ hostname = <%= @imap_hostname %>
 username = <%= @imap_username %>
 password = <%= @imap_password %>
 use_ssl = <%= @imap_use_ssl %>
+folder = <%= @imap_folder %>
 
 [mqtt]
 hostname = <%= @mqtt_hostname %>