Pass toxinidir to the definition of requirements
Pass toxinidir to the definition of requirements

Allow to run tox from any directory.

Change-Id: I5fcfa00e8bd6dd2f46e66e6405a3bb8031f6a67c

rdo-management/ironic-discoverd,openstack/ironic-inspector,openstack/ironic-inspector,rdo-management/ironic-discoverd