HDP CentOS7 support broken
When running on el7 variants, the repo cookbook configures el6 repos for HDP.
Furthermore, it should not attempt to configure the "GA" repo, as there is no "GA" repo for centos7. Otherwise "yum makecache" will fail.
Corrected the logic causing el6 repos to be created, and it also now adheres more closely to the HDP documentation by only creating a single GA or updates repo, not both.