Move to a config file to simplify using this with pm2 and the like

index.js

@@ -2,26 +2,34 @@ var express = require('express');
 var app = express();
 var url = require('url');
 var request = require('request');
+var config = require( './config.json' );
 
 var format = ".json";
-var apikey = process.env.WU_ACCESS  //WU API key; will be set in Heroku
+var apikey = config.apikey;
 
 var bodyParser = require('body-parser');
 app.use(bodyParser.json());
 app.use(bodyParser.urlencoded({ extended: true }));
 
 //use port is set in the environment variable, or 9001 if it isn’t set.
-app.set('port', (process.env.PORT || 9001));
+app.set( 'port', ( config.port || 9001 ) );
 
 //for testing that the app is running
 app.get('/', function(req, res){
-  res.send('Running!!');
+  var msg = 'Running!';
+
+  if ( ! apikey.length ) {
+    msg += ' Please set the API key.'
+  }
+
+  res.send( msg );
 });
 
 //app.post is triggered when a POST request is sent to the URL ‘/post’
 app.post('/post', function(req, res){
-  //take a message from Slack slash command
-  var query = req.body.text
+  if ( ! apikey.length ) {
+    return res.sendStatus( 500 );
+  }
 
   var parsed_url = url.format({
     pathname: 'http://api.wunderground.com/api/' + apikey + '/conditions/q/' + req.body.text + format,