added enabled prop with default true, can disable component from parent (#9)

* added enabled prop with default true, can disable component from parent

* refactored enabled mechanism to remove/add handler

* removed logic from cancelScrollEvent method

* added check to cdm and build

* removed object destructure

Author: jgrisafe

lib/ScrollLock.js

@@ -2,7 +2,17 @@ import React, { Component } from 'react';
 
 class ScrollLock extends Component {
   componentDidMount() {
-    this.scrollingElement.addEventListener('wheel', this.onScrollHandler, false);
+    if (this.props.enabled) {
+      this.scrollingElement.addEventListener('wheel', this.onScrollHandler, false)
+    }
+  }
+
+  componentWillReceiveProps(nextProps) {
+    if (nextProps.enabled) {
+      this.scrollingElement.addEventListener('wheel', this.onScrollHandler, false)
+    } else {
+      this.scrollingElement.removeEventListener('wheel', this.onScrollHandler, false)
+    }
   }
 
   componentWillUnmount() {
@@ -45,4 +55,8 @@ class ScrollLock extends Component {
   }
 }
 
+ScrollLock.defaultProps = {
+  enabled: true
+};
+
 export default ScrollLock;