message: Threw error if context used with old React
diff: @@ -3,6 +3,10 @@ import * as React from 'react';
  var navigationContext;
  if (React.createContext)
  navigationContext = React.createContext(null);
  -else
  - navigationContext = { Provider: null, Consumer: ({children}) => children(null)}
  +else {
  + navigationContext = {
  + Provider: () => { throw Error(`React ${React.version} does not support the new context`) },
  + Consumer: ({children}) => children(null)
  + }
  +}
  export default navigationContext;
  