* Implementing the NewApp function based on the new APIs available in Go API client.

* Renamed package admin to firebase; Updated documentation

* Using JSON key exposed via credential

* Finishing the Go API client integration

* Added some integration tests

* Updated documentation; Using the net/context package where needed

* Added Version constant

* Moved public functions in integration  to integration/internal

* Minor renaming

* Added license and contributing guide. Updated readme.

* Added PR and issue templates

* Added license header to source files

* Added missing newline

* Fixed some typos; Using the firebase.google.com/go URL