Made paths property optional

I'm making a lot of seemingly duplicate commits here, aren't I?

types/node/v8/index.d.ts

@@ -123,7 +123,7 @@ interface NodeRequire extends NodeRequireFunction {
 }
 
 interface RequireResolve {
-    (id: string, options?: { paths: string[]; }): string;
+    (id: string, options?: { paths?: string[]; }): string;
     paths(request: string): string[] | null;
 }