Fix weldSensors() so that it uses newBody instead of currentBody
Change weldSensors() to use currentBody instead of passing in a newBody
Create setupSensor() to simplify sensor creation
Add grab sensor and change extractSensorHeight() to take 2 index values
Incorporate new grab sensor into loser contact listener
Create access to the body in contact with grab sensor
Add null check for currentGrabBody before comparing it to the
contactFixture
Duck can pick up objects but cannot drop them
Let duck pick up and drop objects
Merge branch 'pickup'