Add bindep support

This adds a minimal bindep.txt to install mysql and postgresql
dependencies (copied from nova's bindep.txt). This is needed
now to get python jobs (pep8,py27,etc) working in the gate.

Change-Id: I4b7bccdb7cebd95753e8cd931846213f400aa652
Closes-Bug: #1836087

bindep.txt

@@ -0,0 +1,16 @@
+# This is a cross-platform list tracking distribution packages needed for install and tests;
+# see https://docs.openstack.org/infra/bindep/ for additional information.
+
+# NOTE(mriedem): This list is woefully incomplete but is just listing mysql
+# and postgresql binary dependencies to make tools/test-setup.sh work.
+
+libmysqlclient-dev [platform:dpkg]
+libpq-dev [platform:dpkg test]
+mysql [platform:rpm]
+mysql-client [platform:dpkg]
+mysql-devel [platform:rpm test]
+mysql-server
+postgresql
+postgresql-client [platform:dpkg]
+postgresql-devel [platform:rpm test]
+postgresql-server [platform:rpm]

tox.ini

@@ -117,3 +117,15 @@ ignore = E111,E113,E121,E122,E123,E124,E125,E126,E127,E128,E129,E131,E202,E203,E
 show-source = true
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,tools,build
+
+[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).
+usedevelop = False
+deps = bindep
+commands =
+  bindep test