Refactor drivetrain to use WPILib

[derickson2402]

Drivetrain is currently built using the CTRE Phoenix library, which is how all motors were handled previously.

However, for a differential drivetrain there is no CTRE Phoenix classes to make differential calculations or trajectory following work, so it would have to be implemented by hand.

To fix this, the WPILib should be used to handle the motors instead. This would provide the following benefits:

• Built in differential drivetrain class
• Easy support for gyroscope integration
• Built in shuffleboard dash widgets and configuration

The WPILib brings the following drawbacks compared to Phoenix, but these seem acceptable given the benefits:

• WPILib runs at 50Hz rather than 1000Hz, so 20 times slower. This can be configured differently in the code at the expense of compute power
• Processing done onboard the rio rather than off board on the talon itself
• Some input delay

[derickson2402]

This issue was forgotten about, and has actually been closed.

WPILib encoder classes are only for DIO encoders, so all CTRE hardware must be handled by CTRE Phoenix library. However, the WPILib has built in Kinematics and Odometry helper classes, which offer the desired functionality for mapping controllers to motor outputs.

The code now uses both libraries, and also implements the Shuffleboard dashboard (see #6). In the future, a gyro can also be integrated easily using WPILib.

Closed with 73e017d