escher git dependency

[danolson1]

I am teaching a course on Metabolic Engineering and helping students set up their python environments to use the Escher extension in JupyterLab. Recently several students came across a problem where git is required in order to install the extension. I posted an issue on the JupyterLab github page, and they said the git dependency comes from Escher, and suggested I start an issue here.

-Dan