pip install of mkauthlist

[kadrlica]

There are a few issues with the pip install of mkauthlist

1. We should only upgrade when make upgrade is called. (This was a hack to not throw an error when mkauthlist was already installed.)
2. We need to properly deal with the case where the user does not have root privileges. We are currently doing a pip install --user, but this has the issue that it doesn't add ~/.local/bin to the PATH (pip install --user should check that the user's $PATH is correct pypa/pip#3813). Also note that pip should be added as a dependency (pip dependency #47).

[johannct]

I had another issue related to python2/3 : my python2 pip is pip2, my python3 is pip, and has issues referenced in several places on google. May want to test for the presence of pip2 and default to python2 in case both are present on the system