Added new tester script

[atulmerchia]

Pull Request (PR) into Code-2020

Code Description

New FlexCAN testing utliity

Testing Description

It compiles, but I can't really test manually from home.

Additional Information

Put any additional datasheets, information, and/or useful links here.

Checklist

• Is this code linked to a new board or board rev?
• • Is there a PR for that board in circuits-2020? If so, please pause until that PR is merged.
• Did you test the code in real-world conditions before submitting?
• • Did you use CPU Speed = 76 Mhz and Optimize = Faster when testing?
• Did you pull master into your branch?
• • Did you check for merge conflicts?
• • Did you resolve any that occurred? If you are having trouble or are confused, contact a lead!
• Did you fill out the above template?
• Did you assign the right people for review (on the right)?