Fixed eslint errors.

src/components/ScrollContainer.jsx

@@ -1,9 +1,16 @@
 import React from 'react'
+import PropTypes from 'prop-types'
 
-const ScrollContainer = (props) => {
-  return <div className="maputnik-scroll-container">
-    {props.children}
-  </div>
+class ScrollContainer extends React.Component {
+  static propTypes = {
+    children: PropTypes.node
+  }
+
+  render() {
+    return <div className="maputnik-scroll-container">
+      {this.props.children}
+    </div>
+  }
 }
 
 export default ScrollContainer