Make methods Chainable ⛓, Release 1.2.0

[JRJurman]

Make methods return an instance of the app, so that you can chain multiple methods. This logic is completely backwards compatible, as these methods were previously void.

Resolves #10

Example:

app = new Tram()
  .addRoute('/', () => Tram.html()`<div>Home</div>`)
  .addRoute('/404', () => Tram.html()`<div>Error</div>`)
  .start('.main')

Tram-One Changes

• addReducer returns an instance of this
• addRoute returns an instance of this
• start returns an instance of this
• mount returns an instance of this