defaultValue is always an empty string, value is the correct one

When the component checks whether there is a default filter applied, it fetches the value from defaultValue.
This does not work. defaultValue on the input component is empty.
The value property however, contains the correct value.

Author: jfremy

src/filters/Date.js

@@ -62,7 +62,7 @@ class DateFilter extends Component {
 
   componentDidMount() {
     const comparator = this.refs.dateFilterComparator.value;
-    const dateValue = this.refs.inputDate.defaultValue;
+    const dateValue = this.refs.inputDate.value;
     if (comparator && dateValue) {
       this.props.filterHandler({ date: new Date(dateValue), comparator }, Const.FILTER_TYPE.DATE);
     }