Missing gazebo directory

[mpowelson]

So the launch file has a check to see if the crs_support directory exists(HERE). However it does not check to see if ~/.gazebo/models exists. In my case I had neither.

We could simply add a check for that as well, or we have also made a first time setup launch file in the past. That seems like that might be warranted here. It could set up the file structure needed for the GUI, gazebo, and anything else needed.

[jrgnicho]

I see, I think a simple check to make sure that default directory exist would suffice for now