fix for flow error on html loading by adding declaration for raw-loader module

.flowconfig

// place this one in the [options] section in your flowconfig

module.name_mapper='^raw-loader!\(.*\.html?\)' -> 'raw-loader'

raw-loader.js

// this file should be in flow-typed directory under root folder of your project

declare module 'raw-loader' {
  declare module.exports: string;
}