
We do not need tox_install.sh, pip can handle constraints itself and install the project correctly. Thus update tox.ini and remove the now obsolete tools/tox_install.sh file. This follows https://review.openstack.org/#/c/508061 to remove tools/tox_install.sh. Change-Id: Ib9e007b9eeae5f2079dd682df0c7ef2294961f4f