Add necessary executable permission
Add necessary executable permission

tools/pretty_tox.sh should be marked as executable, this patch
just 'chmod +x' to it.

Closes-Bug: 1486313
Change-Id: Ia5fa921e83da1e094970b1e44c9709272c7e32d3

maestro-hybrid-cloud/keystone,dims/keystone,rajalokan/keystone,roopali8/keystone,mahak/keystone,jamielennox/keystone,mahak/keystone,jonnary/keystone,ilay09/keystone,klmitch/keystone,jonnary/keystone,openstack/keystone,maestro-hybrid-cloud/keystone,rajalokan/keystone,ajayaa/keystone,ajayaa/keystone,ilay09/keystone,takeshineshiro/keystone,mahak/keystone,openstack/keystone,rajalokan/keystone,klmitch/keystone,idjaw/keystone,openstack/keystone,takeshineshiro/keystone,himanshu-setia/keystone,cernops/keystone,himanshu-setia/keystone,cernops/keystone,idjaw/keystone,jamielennox/keystone,roopali8/keystone,dims/keystone,ilay09/keystone