Fixes #66 with coverage of unit test via travis. 

Hi, 

This PR have good and bad things.

Good

1. Removed the shell script
1. Better coverage of unit tests
1. Run phpunit from root without passing the directory

Bad

1. Unit test now relies on composer
1. require-dev of `aura/di` added.

I am not against this way of unit testing for users still can install `aura/router` via `--no-dev` if they don't like.

Let us move this way?

Thoughts ?
Generating code coverage here may not be very interesting. With a lot of lazy loading happening it will not help improve code quality I think.