Prints unicode character instead of icon
Using the default config suggested in the `README`:
```
const IconFontPlugin = require('iconfont-webpack-plugin')
...
loader: 'postcss-loader',
  options: {
    plugins: loader => [new IconFontPlugin(loader)],
  },
````

`font-icon: url('../../static/images/icons/search.svg');`

I am seeing the unicode character instead of the referenced svg as the content. Please advise on how I can fix to see the icon or what steps I can take to debug.