Issue with Webpack and exclamation mark in path

[x8x]

This PR webpack/webpack@04d8188 was merged into Webpack 4.6, it returns better error message to the user, would be good to upgrade webpack version in dev dependency to 4.6 ( now it's 4.5 )

[ulivz]

Will release it at 0.9.0: #419. 🚀