Examine possible usage of Fantomas

The [Fantomas](https://github.com/fsprojects/fantomas) library allows one to format F# code using a pre-defined set of coding guidelines. We should investigate to see if it is useful to integrate Fantomas in our projects. I can envision two approaches:

1. Use the CLI tool to format all of the F# code in this repository: https://github.com/fsprojects/fantomas#command-line-tool--api. This means that not only will our test generator code be consistently formatted, all the tests suites, example and stub implementations will also have the same formatting, which is beneficial for students. Note: this may require some changes to the format in which the generator outputs the test suites, to have it conform to the Fantomas style.
1. Add Fantomas as a CLI tool reference to each exercise's project: https://blog.nojaf.com/2018/05/03/fantomas-rejuvenated/ This will give students the ability to quickly format their code.