Add timeout to close modals automatically

[Munk91]

Hello.

I needed to set a custom timeout to close modals automatically, so I added that. Hope you like it 🛩

Tell me if there is something I need to do, this is my first PR to this project.

[bluefirex]

Hi, thanks for your contribution! 🙏 There are two missing things, though:

1. The parameter "timeout" hasn't been given to the function signature.
2. The project has to be built and the resulting files be committed, too.

[Munk91]

@bluefirex Hello. I tried to build but got some issues - it seems like there are some problems building sourcemaps atm.

It looks like the same as #42

I disabled babili-webpack-plugin in webpack config, so the build could go through.

If you find it neccesary to include sourcemaps - can you try and run it with your own config?

There are some known issues on the source map thingy, check out:

• Error: original.line and original.column are not numbers mozilla/source-map#304
• Update to source-map 0.6.1 causes an error when running Webpack webpack/webpack-sources#28

[Munk91]

@bluefirex Status on review? 😃