AG-1053 Tidy react examples, make more idiomatic

src-examples/richGridExample/ProficiencyCellRenderer.jsx

@@ -0,0 +1,24 @@
+import React from 'react';
+
+// cell renderer for the proficiency column. this is a very basic cell renderer,
+// it is arguable that we should not of used React and just returned a string of
+// html as a normal ag-Grid cellRenderer.
+export default class ProficiencyCellRenderer extends React.Component {
+
+    render() {
+        let backgroundColor;
+        if (this.props.value < 20) {
+            backgroundColor = 'red';
+        } else if (this.props.value < 60) {
+            backgroundColor = '#ff9900';
+        } else {
+            backgroundColor = '#00A000';
+        }
+
+        return (
+            <div className="div-percent-bar" style={{width: this.props.value + '%', backgroundColor: backgroundColor}}>
+                <div className="div-percent-value">{this.props.value}%</div>
+            </div>
+        );
+    }
+}