webpack was making it difficult to get proper stack trace upon hitting an exception
instead of reporting lines within the original.ts, it would only report the transpiled file via ts-loader.

adding "babel-jest" so babel can be used by jest to transform reuqired .ts files on the fly.

https://github.com/project-chip/zap/issues/165

This reverts commit 4703b67a.

BUG: ZAPP-544