Summary:
Replace Eden's old custom `getdeps.py` script with a simple `build.sh` wrapper
that invokes the modern `getdeps.py` tool.
Note that this build script was largely cribbed from the `getdeps.sh` script
in the [fboss](https://github.com/facebook/fboss/) repository.
Reviewed By: wez
Differential Revision: D20688291
fbshipit-source-id: 6f119479280e82a0c28b8b1481fa01611908c566