List system dependencies for running common tests

Add a 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.

This change is self-testing.

For bindep.txt see also
http://docs.openstack.org/infra/manual/drivers.html#package-requirements

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

Change-Id: I736a4e68ab376e64b5f5adf8406c396a631799ee

bindep.txt

@@ -0,0 +1,22 @@
+# This is a cross-platform list tracking distribution packages needed by tests;
+# see http://docs.openstack.org/infra/bindep/ for additional information.
+
+build-essential [platform:dpkg]
+gcc [platform:rpm]
+liberasurecode-dev [platform:dpkg]
+liberasurecode-devel [platform:rpm]
+libffi-dev [platform:dpkg]
+libffi-devel [platform:rpm]
+libxml2-dev [platform:dpkg]
+libxml2-devel [platform:rpm]
+libxslt-devel [platform:rpm]
+libxslt1-dev [platform:dpkg]
+memcached
+python-dev [platform:dpkg]
+python-devel [platform:rpm]
+
+# Needed by swift
+rsync
+xfsprogs
+libssl-dev [platform:dpkg]
+openssl-devel [platform:rpm]

tox.ini

@@ -65,3 +65,14 @@ ignore = H
 select = F,E,W,H102,H103,H501,H903,H231
 exclude = .venv,.git,.tox,dist,doc,*egg,build
 show-source = True
+
+
+[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.
+usedevelop = False
+skip_install = True
+deps = bindep
+commands = bindep test