Add Stryker4s to Testing section
Add Stryker4s to Testing section

Stryker4s is a mutation testing framework. Mutation testing lets you test your tests by introducing small bugs in your code and measuring how much your tests are affected by these. Although it is still in an early stage, Stryker4s uses source code manipulation (unlike, for example, PIT which manipulates bytecode) which is a perfect fit for mutating expressive Scala code. You can read more about Stryker4s (and it's products for other languages) on the [website](https://stryker-mutator.io/)
lauris/awesome-scala,pconcepcion/awesome-scala