Install required packages

Document what is needed for testing and building  -and use this in
our CI.

This uses a bindep.txt file.

Change-Id: Ia5e9ea90e2fcb02d44c74c96a4bfe957b649a856

bindep.txt

@@ -0,0 +1,15 @@
+# This is a cross-platform list tracking distribution packages needed by tests;
+# see http://docs.openstack.org/infra/bindep/ for additional information.
+
+libxml2-dev [platform:dpkg]
+libxml2-devel [platform:rpm]
+libxml2-utils [platform:dpkg]
+libxslt-devel [platform:rpm]
+libxslt1-dev [platform:dpkg]
+python-dev [platform:dpkg]
+python3-all [platform:dpkg !platform:ubuntu-precise]
+python3-all-dev [platform:dpkg !platform:ubuntu-precise]
+python3-devel [platform:fedora]
+python34-devel [platform:centos]
+zlib-devel [platform:rpm]
+zlib1g-dev [platform:dpkg]

tox.ini

@@ -33,6 +33,14 @@ commands =
   rm -rf api-ref/build
   sphinx-build -a -E -W -d api-ref/build/doctrees -b html api-ref/source api-ref/build/html
 
+[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.
+deps = bindep
+commands = bindep test
+
 [flake8]
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,tools
 show-source = True