Added CLI option to specify server port (#1)

diff --git a/src/api/server.coffee b/src/api/server.coffee
index 5fa7b8e..ae2ada4 100644
--- a/src/api/server.coffee
+++ b/src/api/server.coffee
@@ -10,10 +10,11 @@
 require('events').EventEmitter.defaultMaxListeners = 100
 
 yang = require('yang-js')
+argv = require('minimist')(process.argv.slice(2))
 
 require('yang-express').run {
 
-  port: 5050
+  port: argv.port || 5050
   models: [
     yang.require 'cord-core'
     yang.require 'xos-core'