title: Source.pipe is not a function with redux-observable / rxjs/operators
body: <p>Handling a react-native redux-observable project (*sigh...).<br>
  On the configuration of the store it seems I have an error but for the life of my I cannot know why.</p>
  
  <p>Getting the following screen on load.
  <a href="https://i.stack.imgur.com/gDJwu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gDJwu.png" alt="enter image description here"></a></p>
  
  <p>The following is the configuration file: (Everything else is really standard)</p>
  
  <pre><code>import { createStore, applyMiddleware } from 'redux'
  import thunk from 'redux-thunk'
  import logger from 'redux-logger'
  import { createEpicMiddleware, ofType, combineEpics } from 'redux-observable'
  import { composeWithDevTools } from 'redux-devtools-extension'
  import { combineReducers } from 'redux'
  
  import { 
      registerEmailEpic,
  } from './actions'
  
  import {
      masterReducer
  } from './reducers';
  
  const rootReducers = combineReducers({ masterReducer });
  const rootEpics = combineEpics(registerEmailEpic);
  
  const epicMiddleware = createEpicMiddleware();
  
  // App dev + prod middleware.
  // The order matters.
  let middleware = [
      thunk, 
      epicMiddleware,
      combineEpics,
      ofType
  ];
  
  if (__DEV__) {
      const reduxImmutableStateInvariant = require('redux-immutable-state-invariant').default();
      middleware = [...middleware, reduxImmutableStateInvariant, logger];
  } else {
      middleware = [...middleware];
  }
  
  export default function configureStore() {
      const configuredStore = createStore(
          rootReducers,
          composeWithDevTools(applyMiddleware(...middleware))
      );
      epicMiddleware.run(rootEpics);
      return configuredStore;
  }
  </code></pre>