Adding a support for AirSpec, a new testing framework for Scala and Scala.js

I've recently created a new testing framework for Scala and Scala.js, called AirSpec:

https://wvlet.org/airframe/docs/airspec.html

AirSpec simplifies writing tests in Scala because it uses plain Scala functions for defining test cases.

To use AirSpec with IntelliJ, it seems we need to add some integration code around here:

https://github.com/JetBrains/intellij-scala/tree/idea192.x/scala/runners/src/org/jetbrains/plugins/scala/testingSupport

For now, I'm not sure whether supporting AirSpec in IntelliJ is technically feasible or not, but I would be happy to contribute a PR or adding missing functionalities to  AirSpec in order to integrate with IntelliJ IDEA, which is my favorite Scala editor!

Let me know your preference for the process for adding such an integration.

Best Regards,

Taro L. Saito, creator of AirSpec