Minor changes to wheel encoder and touch sensor testing

[jeremyolsen]

Found changes during testing.

The majority of the changes were just setting defaults on the incoming parameters. I was debugging via PyCharms and the params from the launch were not going to be loaded in this scenario, thus the reason for adding them.

The 's' variable needed to be initialized outside the if statement. I got the error while launching in ROS.

[merose]

I think the node name and type are misspelled. Should be "arduino", not "arudino". Will fix after pulling.