Add tox.ini
Add tox.ini

Add initial tox.ini file for integration with OpenStack

Change-Id: I32115bed3cee3fb97fa7dc5622b8f42374e3d1d2

openstack/openstack-doc-tools,savinash47/openstack-doc-tools,savinash47/openstack-doc-tools,openstack/openstack-doc-tools,savinash47/openstack-doc-tools