Stop configuring install_command in tox.
Stop configuring install_command in tox.

It turns out that this is the the default value provided by tox:

https://tox.readthedocs.io/en/latest/config.html#conf-install_command

So we can remove the line and simply use the default value.

Change-Id: Id3a4bc58d0322205456156808e482e9a137b3029
Co-Authored-By: tushargite96 <d6f5d7404354e8bbc6da6ee6e98dc4ac60967cc7@gmail.com>

openstack/puppet-trove,openstack/puppet-trove,openstack/puppet-trove