OpenFermion pip installation requires write access to package files

[kevinsung]

The following was reported by Burt Holzman from Fermilab, who installed OpenFermion in a docker image:

PS The hackiest thing in there is changing the ownership in openfermion (which is installed under a root-controlled /opt/conda) to the notebook user. I didn't look at the code, but for some reason it expects write access in site-packages ...

This might have something to do with some code requiring access to the src/data/ directory. We should investigate.

[babbush]

This is a "problem" we've been aware of since the earliest days of development. But we haven't been able to come up with a satisfactory alternative.

[kevinsung]

I guess this would be addressed by #270