Improove flow

Author: bagratinho

src/components/core/filters/filter-group.jsx

@@ -12,7 +12,7 @@ type State = {
 };
 
 type DefaultProps = {
-  renderCount: Function,
+  renderCount: (count: number) => string,
 };
 
 export default class FilterGroup extends Component {

src/components/core/filters/types.js

@@ -16,7 +16,7 @@ export type FilterTypeProps = {
   onSelectFacet?: Function,
   term?: string,
   values?: Array<FilterValue>,
-  renderCount: Function,
+  renderCount: (count: number) => string,
 };
 
 
@@ -28,5 +28,5 @@ export type FilterGroupProps = {
   onClearFacet?: Function,
   onSelectFacet?: Function,
   initiallyExpanded?: boolean,
-  renderCount?: Function,
+  renderCount?: (count: number) => string,
 };