Fix get-pipsy.py to say ~/.local/bin instead of %s

Looks like the original intention was to interpolate the pipsi bin directory - replacing the `%s` with just `~/.local/bin` instead. It's hardcoded, but so is the export instruction a few lines down.
Merge pull request #1 from joshma/master

Fix get-pipsy.py to say ~/.local/bin instead of %s