Merge pull request #39 from BFALacerda/hydro-devel

switching from strands_datacentre to ros_datacentre in bob-bringup
Changing from strands_datacentre to ros_datacentre on linda launch file
Merge pull request #41 from Jailander/hydro-devel

Changing from strands_datacentre to ros_datacentre on linda launch file
now uses hydro read-only
adding strands_navigation to strands-base.yaml