FIX: Tilde expansion and Github URLs

@drammock The tilde expansion doesn't work in scripts by default, so I changed that to use an environment variable. It would just create a new directory named '~/Builds' at the pwd when the script was run.

For some reason, none of the URLs worked for me. I'm not sure if there is a simple reason or not, but I updated each by copy/pasting them off each repo's clone link.
The note about key auth should go around line 75, methinks. (Can't do line comments on lines that haven't changed, else I would have put this note there).