Update git-bash install instructions

[pshriwise]

There is an option when installing git-bash on windows machines that needs to be checked related to allowing the installer to set their PATH environment variable.

At the previous workshop, this option was sometimes checked. We should make sure this is very clear in the setup instructions for this workshop. (Maybe update screenshots if they exist)

[gonuke]

There is also a problem with Anaconda's path relative to git-bash, and Anaconda's recommendation AGAINST changing the system PATH on installation.