Fix bug: Duplicate declaration "PropTypes"

Fix bug: TypeError node_modules/react-native-easy-toast/index.js: Duplicate declaration "PropTypes"

Author: scue

index.js

@@ -18,7 +18,6 @@ import {
 } from 'react-native'
 
 const ViewPropTypes = RNViewPropTypes || View.propTypes;
-import {PropTypes} from 'prop-types';
 export const DURATION = {
  LENGTH_LONG: 2000,
  LENGTH_SHORT: 500,