Tests: Add environment variables for verbosity and log directory

Tests: Add environment variables for verbosity and log directory

Observed issue
==============

When working locally with test failures, changes to `utils.sh` are often
required to produce verbose output.

Solution
========

By adding environment variables to allow running the various tools
with higher verbosity and potentially outputting to either stderr or
temporary files in a given directory test runners now have the option
to quickly get more information.

Known drawbacks
===============

Some tests depend on parsing either stderr or stdout, and these global
defaults may potentially make developing robust tests more
complicated.

Change-Id: I4128c421cdf9ce12827adc017dba5a298b62b6de
Signed-off-by: Kienan Stewart <kstewart@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>