Merge pull request #5 from RARyan/RobMasterBranch

Attempting to implement some JUnit testing classes.
Added the Sensor abstract class.
Merge branch 'master' of https://github.com/RARyan/PACSim
Merge branch 'master' of https://github.com/RARyan/PACSim
Added the method getType() to the Sensor class. Modified the Sensor
constructor to accept a type assignment (accelerometer, gyroscope, etc.)
in the form of an integer.