remove createReactClass from ProgressViewIOS.ios.js (facebook#21887)

Summary:
Related to facebook#21581 .
Removed createReactClass from the Libraries/Components/ProgressViewIOS/ProgressViewIOS.ios.js

- [x] npm run prettier
- [x] npm run flow-check-ios
- [x] npm run flow-check-android
[GENERAL] [ENHANCEMENT] [Libraries/Components/ProgressViewIOS/ProgressViewIOS.ios.js] - remove createReactClass dependency
Pull Request resolved: facebook#21887

Differential Revision: D10491704

Pulled By: RSNara

fbshipit-source-id: a38f87b9c151aaac8885edd22ce852ee2f2cf746

Libraries/Components/ProgressViewIOS/ProgressViewIOS.ios.js

@@ -13,7 +13,6 @@
 const React = require('React');
 const StyleSheet = require('StyleSheet');
 
-const createReactClass = require('create-react-class');
 const requireNativeComponent = require('requireNativeComponent');
 
 import type {NativeComponent} from 'ReactNative';