1.0

/to @bajtos 
/cc @raymondfeng 

Please review the following.

https://github.com/strongloop/loopback-phase/blob/1.0/example/middleware.js => example for our middleware use case.

https://github.com/strongloop/loopback-phase/blob/1.0/test/phase.test.js => the phase API / test

https://github.com/strongloop/loopback-phase/blob/1.0/test/phase.test.js => the phaseSet API / test

Also take a look at the example in the README.md. Everything else is copied from loopback-boot.
I find this API inflexible, as there is no way how to execute the phase on itself, without calling next phases. For me, this is another indicator that the class is designed in a wrong way and that `prev` & `next` don't belong to `Phase`.