fix build error

mod.ts

@@ -1 +1 @@
-export { Composable } from "./composable.ts";
+export { PromiseChain } from "./promise-chain.ts";

promise-chain.bench.ts

@@ -1,4 +1,4 @@
-import PromiseChain from "./promise-chain.ts";
+import { PromiseChain } from "./promise-chain.ts";
 import { TestClass } from "./stubs/test-class.ts";
 
 const iterate = (

promise-chain.test.ts

@@ -2,7 +2,7 @@ import {
   assert,
   assertEquals,
 } from "https://deno.land/std@0.154.0/testing/asserts.ts";
-import PromiseChain from "./promise-chain.ts";
+import { PromiseChain } from "./promise-chain.ts";
 import { TestClass } from "./stubs/test-class.ts";
 
 Deno.test(async function whenTraditionalAsyncChainingItReturnsResult() {

promise-chain.ts

@@ -4,7 +4,7 @@ import { AsyncComposable } from "./types.ts";
  * Utility class to wrap a composition class with the intended purpose of chaining methods, specifically useful for
  * functions that return Promises. Note: Promise functions and non-promise functions can be mixed.
  */
-export default class PromiseChain<T> extends Promise<T> implements Promise<T> {
+export class PromiseChain<T> extends Promise<T> implements Promise<T> {
   /**
    * Create a chaninable class based off of the functions that return "this" or a Promise of "this".
    */