Add missing ref.props.scrollIntoView method (#258)

The imperative method is not exposed currently

Author: slorber

lib/KeyboardAwareHOC.js

@@ -410,6 +410,7 @@ function listenToKeyboardEvents(ScrollableComponent: React$Component) {
           scrollToEnd={this.scrollToEnd}
           scrollForExtraHeightOnAndroid={this.scrollForExtraHeightOnAndroid}
           scrollToFocusedInput={this.scrollToFocusedInput}
+          scrollIntoView={this.scrollIntoView}
           resetKeyboardSpace={this._resetKeyboardSpace}
           handleOnScroll={this._handleOnScroll}
           onScroll={Animated.forkEvent(onScroll,this._handleOnScroll)}