Add dep8 tests
this MR is to add DEP8 tests to the sssd package.
Here is an autopkgtest run using a debian/sid lxd container: http://people.ubuntu.com/~ahasenack/dep8-sssd-debian-1.16.3-2/
I plan to add these tests to Ubuntu as well, but since sssd is currently a sync. I would like to get it into Debian first.
Please let me know what you think.