grosser/parallel_tests — pull request #188 by aripollak (2013-03-18 14:15:56+00:00)
Title: Hide errors from "set -o pipefail"

When using zsh, I always get the following when running `rake parallel:prepare`:
```
sh: 1: set: Illegal option -o pipefail
```

This patch hides errors from trying to test for pipefail, since it's not really useful.