Fix error TS2497 on import * as X from 'statsd-client':

Per Microsoft/TypeScript#5073, closed as `By Design` by @mhegazy, we need to
export a namespace for `import *` to work, else `TS2497`. That clashes with
the `export = ClassName` pattern unless you also merge in a namespace, e.g.
with `namespace ClassName {}`.

statsd-client/statsd-client-import-asterisk-tests.ts

@@ -0,0 +1,3 @@
+/// <reference path="statsd-client.d.ts" />
+import * as StatsdClient from 'statsd-client';
+const statsd = new StatsdClient({ debug: true });

statsd-client/statsd-client.d.ts

@@ -99,5 +99,6 @@ declare module "statsd-client" {
 		getChildClient(name: string): StatsdClient;
 	}
 
+	namespace StatsdClient {}
 	export = StatsdClient;
 }