Error with missing regeneratorRuntime

[akofman]

With the actual version of babel-preset-react-app, we have two different versions of babel-plugin-transform-regenerator :

$npm ls babel-plugin-transform-regenerator 
babel-preset-react-app@0.2.1 
├── babel-plugin-transform-regenerator@6.14.0
└─┬ babel-preset-latest@6.14.0
  └─┬ babel-preset-es2015@6.16.0
    └── babel-plugin-transform-regenerator@6.16.1

This prevents to use storybook without babel-polyfill. I did a PR to creat-react-app to fix this issue. Once it will be released, we should update the version of babel-preset-react-app.

[arunoda]

I'll bump the version when it's published.
We we use semvar, you could simply do a clean node_modules and install deps again to fix this issue on the Storybook side.