Include custom themes about bootstrap-webpack

[pochemuto]

Issues was with redundant import bootstrap-webpack in js code:
import "bootstrap-webpack";

[pochemuto]

So, yes. The problem is there. Import was redundant but removing them didn't help.
The problem is related that ticket #23

I found workaround:
create somewhere in your app folder bootstrap.less file with following content:

@import "~bootstrap/less/mixins";
@import "theme/lumen/variables";
@import "theme/lumen/bootswatch";

bootswatch requires variables and last one might have bootstrap dependencies. In my case it was mixins.

Add file path to entry in webpack.config.js:

module.exports = {
    context: __dirname + "/app",
    entry: ['!!bootstrap-webpack!../bootstrap.config.js', './client/index.ts', './client/css/bootstrap.less'],
    output: ...

And then it will work.