message: Removed dummy NavigationContext
  Was only there so it could work with all version of React
diff: import * as React from 'react';
  -var navigationContext;
  -if (React.createContext)
  - navigationContext = React.createContext(null);
  -else {
  - navigationContext = {
  - Provider: () => { throw Error(`React ${React.version} does not support the new context`) },
  - Consumer: ({children}) => children(null)
  - }
  -}
  -export default navigationContext;
  +export default React.createContext(null);
  