Add settings to install MongoDB on a separate target

[yanickrochon]

I am not sure if mup can do this already, but I haven't read anywhere that it can.

I am looking at ways to setup multiple VMs, one of which would be the MongoDB host. It would be nice that mup would install and configure Mongo on a specific host. Something like

  // Server authentication info
  "servers": [
    {
      "host": "10.0.1.11",
      "username": "root",
      "password": "password",
      "env": {
        "MONGO_URL": "mongodb://root:[email protected]:10023/MyApp",
      }
    },
    {
      "host": "10.0.1.12",
      "username": "root",
      "password": "password",
      "env": {
        "MONGO_URL": "mongodb://root:[email protected]:10023/MyApp",
      }
    }
  ],
  "mongodb": {
    "host": "10.0.1.10",
    "user": "root",
    "password": "password"
  }
}