Move path additions to .zshenv

By moving path additions from .zshrc to .zshenv the path is updated for
applications which are not launched from an interactive shell (e.g.
urxvt -e vim).

Signed-off-by: Austin M. Matherne <AustinMatherne@Gmail.com>
Add CasperJS git repo pull to update command

Signed-off-by: Austin M. Matherne <AustinMatherne@Gmail.com>