Rheostat initialize creates a conflict with React-dates initialize

If you install both packages they are unable to work, they seem to overwrite each other since v3.0.0 😞

...
"react-dates": "^16.7.0",
"rheostat": "^3.0.0",
...

[majapw]

@castrolem Ahhh thank you for bringing this to our attention. :X This is the usage we should have thought about (since it is our own) and added to the README when we release this major version. If you want to get both working, right now, the easiest way to do so is to do the following instead of importing the initialize script:

import 'rheostat/css/rheostat.css';
import 'react-dates/lib/css/_datepicker.css';

import ThemedStyleSheet from 'react-with-styles/lib/ThemedStyleSheet';
import cssInterface from 'react-with-styles-interface-css';
import RheostatDefaultTheme from 'rheostat/lib/themes/DefaultTheme';
import ReactDatesDefaultTheme from 'react-dates/lib/theme/DefaultTheme';

ThemedStyleSheet.registerInterface(cssInterface);
ThemedStyleSheet.registerTheme({ 
  ...RheostatDefaultTheme,
  ...ReactDatesDefaultTheme,
});

I’ll add this to the README (here and in react-dates) as well as the motivation behind moving to react-with-styles and dealing with these global themes and interfaces while we mull over how we can improve this process.

@ljharb @lencioni for thoughts on this as well.

[ljharb]

Maybe instead of having the defaults overwrite the theme, it should merge them, allowing the namespaces to prevent collisions?