Modify smtpd to integrate with Revel.

Add plugin to app.go to start smtpd

conf/app.conf

@@ -6,6 +6,8 @@ http.port=9000
 [dev]
 results.pretty=true
 server.watcher=true
+smtpd.domain=skynet
+smtpd.port=2500
 
 log.trace.output = off
 log.info.output  = stderr
@@ -15,6 +17,8 @@ log.error.output = stderr
 [prod]
 results.pretty=false
 server.watcher=false
+smtpd.domain=skynet
+smtpd.port=2500
 
 log.trace.output = off
 log.info.output  = off