Added bindep.txt to the project

It allows to avoid installing unnecessary packages while preparing enviroment
for testing.

Change-Id: I6b993b2c2fd56c7517e6cc41efc07bf4a83ff945

bindep.txt

@@ -0,0 +1,11 @@
+# This file contains runtime (non-python) dependencies
+# More info at: http://docs.openstack.org/infra/bindep/readme.html
+
+libffi-dev [platform:dpkg]
+libffi-devel [platform:rpm]
+gcc [platform:rpm]
+gcc [platform:dpkg]
+python-dev [platform:dpkg]
+python-devel [platform:rpm]
+openssl-devel [platform:rpm]
+libssl-dev [platform:dpkg]

tox.ini

@@ -161,3 +161,12 @@ deps = pip_check_reqs
 commands=
     pip-extra-reqs -d --ignore-file=tempest/tests/* tempest
     pip-missing-reqs -d --ignore-file=tempest/tests/* tempest
+
+
+[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