Bump webpack from 1.15.0 to 4.12.0

Bumps [webpack](https://github.com/webpack/webpack) from 1.15.0 to 4.12.0.
- [Release notes](https://github.com/webpack/webpack/releases)
- [Commits](https://github.com/webpack/webpack/commits/v4.12.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-support

package.json

@@ -44,7 +44,7 @@
     "jison": "^0.4.13",
     "jison-loader": "^1.0.0",
     "nodeunit": "^0.11.2",
-    "webpack": "^1.13.2"
+    "webpack": "^4.12.0"
   },
   "types": "main.d.ts"
 }