Changed to full blown source map files and enabled typescript sourcemaps in the compiler

tsconfig.json

@@ -4,7 +4,8 @@
     "module": "commonjs",
     "moduleResolution": "node",
     "outDir": "dist",
-    "declaration": true
+    "declaration": true,
+    "sourceMap": true
   },
   "exclude": [
     "node_modules",

webpack.dev.js

@@ -2,5 +2,5 @@ var merge = require('webpack-merge')
 var common = require('./webpack.common.js')
 
 module.exports = merge(common, {
-    devtool: process.env.DEBUG ? false : 'cheap-eval-source-map'
+    devtool: process.env.DEBUG ? false : 'source-map'
 })