update tests with scalamock and scalacheck

[vickumar1981]

the tests just run a few hard-coded values to makes sure the inputs and outputs match.

on top of those surface level tests, i'd like to add the scalamock and scalacheck libraries and use a set of property-based tests to make sure that algorithms work as intended. the sound/phonetic algorithms are currently not really tested b/c of this

https://scalamock.org/
https://www.scalacheck.org/