fix: change directories after HOME is setup
fix: change directories after HOME is setup

Some `profile.d` files may end up referencing files that are in `$HOME` via relative paths. As this functionality works on Heroku, we should attempt to emulate it as best we can.

Refs heroku/heroku-buildpack-php#450
gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,gliderlabs/herokuish