Merge pull request #247 from BCLab-UNM/template_model_readme_catkin_fix

Updated readme to say catkin has to be run

Author: gmfricke

simulation/models/swarmie/README.md

@@ -4,4 +4,4 @@ erb -T - rovername=name rovercolor=color -- model.sdf.erb > model.sdf
 ```
 
 NOTE: You should use `misc/gen_rover_models.sh` to generate the all of the default
-rover models.
+rover models. Before you can use the script the catkin workspace has to be configured (catkin build).