Add support for broker URLs

[jupiter]

In our IBM Bluemix investigation, we found that they prefer to use URLs for configuration. We should implement an optional setting of MSB_BROKER_URL, which would define the adapter, host, port, username and password.

For AMQP as per https://www.rabbitmq.com/uri-spec.html and for Redis, something like redis://[:password@]host[:port][/db-number].

[nfantone]

I've implemented a simple parser just for that, here:

https://github.com/disintegrator/seneca-amqp-transport/blob/develop/lib/amqp-uri.js

No redis:// protocol support, tough.

[jupiter]

@nfantone This creates an URL, right? I think it will be trivial to parse an AMQP and Redis URL using core URL, e.g. require('url').

[nfantone]

@jupiter

This creates an URL, right?

It does. Converts an object like:

 {
    hostname: 'dev.rabbitmq.com',
    port: 5672,
    vhost: 'seneca',
    username: 'guest',
    password: 'guest',
    frameMax: 1024
  }

to an URI like amqp://guest:guest@dev.rabbitmq.com:5672/seneca?frameMax=1024.

I think it will be trivial to parse an AMQP and Redis URL

You mean you actually need the other way around: turn an URI into an object. Yes, it is as trivial as:

var url = require('url');
url.parse('amqp://guest:guest@dev.rabbitmq.com:5672/seneca?frameMax=1024')
Url {
  protocol: 'amqp:',
  slashes: true,
  auth: 'guest:guest',
  host: 'dev.rabbitmq.com:5672',
  port: '5672',
  hostname: 'dev.rabbitmq.com',
  hash: null,
  search: '?frameMax=1024',
  query: 'frameMax=1024',
  pathname: '/seneca',
  path: '/seneca?frameMax=1024',
  href: 'amqp://guest:guest@dev.rabbitmq.com:5672/seneca?frameMax=1024' }

It's not exactly the same thing, though. Query string remains a string, for instance. And you don't have support for username, password and such.