Fix loic-sharma#490 - package last updated date (loic-sharma#491)

Fixes loic-sharma#490 by using `Date.prototype.toLocaleDateString()` to format date values used to show when a package was last updated.

src/BaGet.UI/src/DisplayPackage/Versions.tsx

@@ -99,6 +99,6 @@ export class Versions extends React.Component<IVersionsProps, IVersionsState> {
   private showFewerVersions = () => this.setState({ showAll: false });
 
   private dateToString(date: Date): string {
-    return `${date.getMonth()+1}/${date.getDate()}/${date.getFullYear()}`;
+    return date.toLocaleDateString();
   }
 }