Specify length of toArrary return value

toArray will always return an array with seven numbers. This change is necessary to be able to do `new Date(...m.toArray())`. As just `number[]`, it complains with `Expected 0-7 arguments, but got 0 or more.`.

moment.d.ts

@@ -585,7 +585,7 @@ declare namespace moment {
 
     diff(b: MomentInput, unitOfTime?: unitOfTime.Diff, precise?: boolean): number;
 
-    toArray(): number[];
+    toArray(): [number, number, number, number, number, number, number];
     toDate(): Date;
     toISOString(keepOffset?: boolean): string;
     inspect(): string;