Make beta required to pass on travis again. (#67)
Make beta required to pass on travis again. (#67)

Upstream bug https://github.com/rust-lang/rust/issues/47175 is fixed, so we enable beta again as required for passing.
cartographer-project/point_cloud_viewer,googlecartographer/point_cloud_viewer,cartographer-project/point_cloud_viewer,googlecartographer/point_cloud_viewer,googlecartographer/point_cloud_viewer,googlecartographer/point_cloud_viewer,cartographer-project/point_cloud_viewer,googlecartographer/point_cloud_viewer,cartographer-project/point_cloud_viewer,cartographer-project/point_cloud_viewer