fix eslint warnings

lib/ObjectCellRenderer.js

@@ -1,22 +1,31 @@
-import React from 'react';
+import React, { PropTypes }  from 'react';
 
-export default (props)=> {
+const ObjectCellRenderer = (props)=> {
     const Renderer = props.config.cellRendererBase;
     const columns = props.columns;
     const columnName = props.columnName;
     const object = props.object;
 
     const items = Object.keys(props.value).map((key) => {
-        return(
-        [
+        return [
             <dt>{key}</dt>,
             <dd><Renderer config={props.config} value={props.value[key]} object={object} columns={columns} columnName={columnName}/></dd>
-        ]
-            );
+        ];
     });
     return(
-                <dl>
-                    {items}
-                </dl>
-        );
+        <dl>
+            {items}
+        </dl>
+    );
 };
+
+ObjectCellRenderer.propTypes = {
+    config : PropTypes.object.isRequired, // TODO: refine
+    columns: PropTypes.object.isRequired, // TODO: refine
+    columnName: PropTypes.string.isRequired,
+    object: PropTypes.object.isRequired,
+    value: PropTypes.object.isRequired
+
+};
+
+export default ObjectCellRenderer;