Remove projects tox environment
Remove projects tox environment

Since projects is not used anymore (it was merged with the gerrit
environment), this can be removed now.

Change-Id: Ic9693c9660cd8ca1e29da0405b7f5704c908b778

openstack-infra/project-config,Tesora/tesora-project-config,Tesora/tesora-project-config,dongwenjuan/project-config,dongwenjuan/project-config,openstack-infra/project-config