Install script needs bash >= 4.0

[StephanEggermont]

On my Yosemite 10.10.5 Mac, the bash version is 3.2.57(1)

According to http://www.catonmat.net/download/bash-redirections-cheat-sheet.pdf

cmd1 |& cmd2

Redirect stdout and stderr of cmd1 to stdin of cmd2 (bash 4.0+ only). Use cmd1 2>&1 | cmd2 for older bashes.