Drive science cleanup

[ozheng2]

I cleaned up science.proto and drive.proto. I compared the respective .ino files, the .pb.h files, and other files for references to the variables in the .proto files.

Science.proto:

• Removed version variables from ScienceCommand and ScienceData since I found no references to them

Drive.proto:

• Removed version variable from DriveCommand since no references were found
• Removed rpm variables from DriveData since no references were found
• Added has_version variable to DriveData since drive.ino uses it

[Kenou2005]

Everything else looks good, but we do want to keep the back_left, middle_left...etc fields for the motor speed This is in preparation for future incorpration.

[ozheng2]

I added the motor rpm fields back to drive.proto