GitLab

Should be explicitly created by the runtime later and set.

Do not assume that everything is running from the repo. Finding things
relative to the python script paths is also broken once packages get
installed via pip etc. For now just default to having SimBricks under
/simbricks or else this has to be set in the environment.

`symphony-dev` sets up the current python environment for development.
Includes installing required dependencies and then editable installs for
each simbricks python package.

`symphony-build` build wheels and source packages for all simbricks
python packages in `symphony/dist/`.