Import rubygem-rkerberos for EL7
EL6 build of rubygem-sinatra not required
Import rubygem-sinatra for EL7
Import rubygem-tilt for EL7
Import rubygem-rack-protection for EL7
Import rubygem-rack for EL7
Import rubygem-mime-types for EL7
Import rubygem-ffi for EL7
Update minimum tito version
Add tito configuration
