dist/redhat: support RHEL8
dist/redhat: support RHEL8

Since RHEL7 and RHEL8 has different pacakge name for pyyaml,
we need to use a file path to resolve the package name on current
distribution.

Signed-off-by: Takuya ASADA <4ebfb6f510af412d6e89fefa3ab96d9c8b5e3fff@scylladb.com>
Message-Id: <20190618014020.26340-1-4ebfb6f510af412d6e89fefa3ab96d9c8b5e3fff@scylladb.com>

scylladb/scylla-tools-java,scylladb/scylla-tools-java,scylladb/scylla-tools-java,scylladb/scylla-tools-java