Update sinon-chai.d.ts

declare module chai {
    interface Expect {
callCount(count: number): Expect;
  }
}

Added --> callCount(count: number): Expect;

sinon-chai/sinon-chai.d.ts

@@ -11,6 +11,7 @@ declare module chai {
         calledOnce: Expect;
         calledTwice: Expect;
         calledThrice: Expect;
+        callCount(count: number): Expect;
         calledBefore(spy: Function): Expect;
         calledAfter(spy: Function): Expect;
         calledWithNew: Expect;