Teach flutter init how to depend on flutter using a relative path - #51

@devoncarew

lgtm! We'll need to update docs to clarify how users should get getting the flutter repo and setting up env. variables and such.

We'll need to update docs to clarify how users should get getting the flutter repo and setting up env. variables and such.

The end-user won't need to set up any env variables. The bin/flutter script sets up everything by looking at its own path in the file system. It actually does all the work of running pub on flutter_tools and compiling the snapshot, etc. Eventually it will also pull down a copy of the Dart SDK so that the "getting started" instructions will just be:

1. Clone the repo
2. Run flutter init -o my_project