Add 'Deploy to Heroku' functionality.

Procfile

@@ -0,0 +1 @@
+web: node server.js

README.md

@@ -5,6 +5,8 @@ cgm-remote-monitor (a.k.a. NightScout)
 [![Dependency Status](https://david-dm.org/nightscout/cgm-remote-monitor.png)](https://david-dm.org/nightscout/cgm-remote-monitor)
 [![Gitter chat](https://badges.gitter.im/nightscout.png)](https://gitter.im/nightscout/public)
 
+[![Deploy to Heroku](https://www.herokucdn.com/deploy/button.png)](https://heroku.com/deploy)
+
 This acts as a web-based CGM (Continuous Glucose Montinor) to allow
 multiple caregivers to remotely view a patients glucose data in
 realtime.  The server reads a MongoDB which is intended to be data

app.json

@@ -0,0 +1,13 @@
+{
+  "name": "CGM Remote Monitor",
+  "repository": "https://github.com/nightscout/cgm-remote-monitor",
+  "env": {
+    "MONGO_COLLECTION": {
+      "description": "The mongo collection to connect to.",
+      "value": "nightscout"
+    }
+  },
+  "addons": [
+    "mongolab"
+  ]
+}

env.js

@@ -23,8 +23,8 @@ function config ( ) {
   env.name = software.name;
   env.DISPLAY_UNITS = process.env.DISPLAY_UNITS || 'mg/dl';
   env.PORT = process.env.PORT || 1337;
-  env.mongo = process.env.MONGO_CONNECTION || process.env.CUSTOMCONNSTR_mongo;
-  env.mongo_collection = process.env.CUSTOMCONNSTR_mongo_collection || 'entries';
+  env.mongo = process.env.MONGO_CONNECTION || process.env.CUSTOMCONNSTR_mongo || process.env.MONGOLAB_URI;
+  env.mongo_collection = process.env.CUSTOMCONNSTR_mongo_collection || process.env.MONGO_COLLECTION || 'entries';
   env.settings_collection = process.env.CUSTOMCONNSTR_mongo_settings_collection || 'settings';
   var shasum = crypto.createHash('sha1');
   var useSecret = (process.env.API_SECRET && process.env.API_SECRET.length > 0);