Add bindep support

Add an bindep.txt file containing a cross-platform list of
dependencies needed for running included tox-based tests. Also include a
tox environment for convenience calling the bindep[*] utility to list
any missing system requirements.

Cyborg requires package 'pciutils' because it is required for running
'lspci' command, this patch also add it.

[*] http://docs.openstack.org/infra/bindep/

Change-Id: If8eca0bcc187aed9fb2ef6794171a1acbc202079

bindep.txt

@@ -0,0 +1,5 @@
+# This file contains runtime (non-python) dependencies
+# More info at: http://docs.openstack.org/infra/bindep/readme.html
+
+# Required for running the 'lspci' command
+pciutils

tox.ini

@@ -35,6 +35,18 @@ envdir = {toxworkdir}/venv
 commands =
     oslo-config-generator --config-file=tools/config/cyborg-config-generator.conf
 
+[testenv:bindep]
+# Do not install any requirements. We want this to be fast and work even if
+# system dependencies are missing, since it's used to tell you what system
+# dependencies are missing! This also means that bindep must be installed
+# separately, outside of the requirements files, and develop mode disabled
+# explicitly to avoid unnecessarily installing the checked-out repo too (this
+# further relies on "tox.skipsdist = True" above).
+basepython = python3
+deps = bindep
+commands = bindep test
+usedevelop = False
+
 
 [testenv:pep8]
 basepython = python3