create Bike class

[mapr7]

create a bike class to inherit the crankshaft, crankset and cassette classes into a bike assembly

add the force/torque calculation to this method

[mapr7]

Implemented Bike class with inheritance from the subcomponents

TO DO:

• [x] calcGearOverlap()
• [ ] simRide()
• [x] changeCassette()
• [x] changeCrankshaft()
• [x] changeCrankset()
• [ ] Thorough method testing