Add the stdout output to the SubprocessException.
Add the stdout output to the SubprocessException.

In some cases, this gives you more information about
why the subprocess failed.

Signed-off-by: Chris Lalancette <281cd07d7578d97c83271fbbf2faddb83ab3791c@gmail.com>

ndonegan/oz,clalancette/oz,nullr0ute/oz,nullr0ute/oz,imcleod/oz,clalancette/oz,imcleod/oz,ndonegan/oz