message: fixed docs to reflect changes
diff: @@ -7,7 +7,7 @@ const {Reshuffle, CronService} = require('reshuffle');
  const app = new Reshuffle();
  const cronService = new CronService();
  -app.use(cronService);
  +app.register(cronService);
  app.when(cronService.on({'interval':5000}), (event) => {
  console.log('Hello World!')
  @@ -29,7 +29,7 @@ const {Reshuffle, HttpService} = require('reshuffle');
  const app = new Reshuffle();
  const httpService = new HttpService();
  -app.use(httpService);
  +app.register(httpService);
  app.when(httpService.on({'method':'GET','path':'/test'}), (event) => {
  event.res.end("Hello World!");
  @@ -50,7 +50,7 @@ httpService.on({'method':'GET','path':'/test'}).do((event) => {
  });
  ```
  -Note: Remember to add the *app.use(service)* prior to *when(...)* or *on(...)*.
  +Note: Remember to add the *app.register(service)* prior to *when(...)* or *on(...)*.
  More examples can be found here [TBD]
  @@ -69,10 +69,11 @@ const connectionOptions = {
  };
  const httpService = new HttpService();
  -app.use(httpService);
  +app.register(httpService);
  -const slackService = new SlackService(connectionOptions);
  -app.use(slackService, 'services/Slack');
  +// the 2nd parameter is used to identify the service later on
  +const slackService = new SlackService(connectionOptions, 'services/Slack');
  +app.register(slackService);
  app.when(httpService.on({'method':'GET','path':'/test'}), (event) => {
  event.getService('services/Slack')
  @@ -81,7 +82,7 @@ app.when(httpService.on({'method':'GET','path':'/test'}), (event) => {
  app.start();
  ```
  -Service objects expose the API and Events that the external service (from a DB to an ERP) provides. You can specify an id when you register a service to the app with the *use(service, serviceId)* and then access that service using the *getService(serviceId)* method.
  +Service objects expose the API and Events that the external service (from a DB to an ERP) provides. You can specify an id when you register a service to the app with the *register(service)*, providing a identifier in the service constructor, and then access that service using the *getService(serviceId)* method.
  You noticed in the code sample that we provided important information on how to connect to the 3rd party system (in that case, Slack). *Services* are an easy way to separate the connection configuration from your code, configure a connection to a service once and use it anywhere.
  @@ -102,8 +103,8 @@ const connectionOptions = {
  'team':'ourTeam',
  };
  -const slackService = new SlackService(connectionOptions);
  -app.use(slackService, 'services/Slack');
  +const slackService = new SlackService(connectionOptions, 'services/Slack');
  +app.register(slackService);
  const eventOptions = {
  'event_type':'new_message',
  