Now keystoneauth uses HTTP_X_TENANT_NAME/ID only even if v3 token uses for
backward compatibility. There is no problem with current behavior because
keystonemiddleware set same value on the headers but the headers are
specified as deprecated so this patch allows to support HTTP_X_PROJECT_NAME/ID
in addition to HTTP_X_TENANT_NAME/ID.
Change-Id: Ie5e02067a59e18f1ac215f51429863bdd42f729f