fixed picker import

src/basic/Picker.js

@@ -2,7 +2,7 @@
 /* eslint-disable react/prefer-es6-class */
 import React, { Component } from 'react';
 import createReactClass from 'create-react-class';
-import Picker from '@react-native-community/picker';
+import { Picker } from '@react-native-community/picker';
 import { connectStyle } from 'native-base-shoutem-theme';
 
 import mapPropsToStyleNames from '../utils/mapPropsToStyleNames';