Use promisify

Signed-off-by: Tiago Martins Nápoli <napoli.tiago96@gmail.com>

index.js

@@ -1,8 +1,11 @@
 'use strict';
 const {constants: BufferConstants} = require('buffer');
 const {pipeline} = require('stream');
+const {promisify} = require('util');
 const bufferStream = require('./buffer-stream');
 
+const streamPipelinePromisified = promisify(pipeline);
+
 class MaxBufferError extends Error {
 	constructor() {
 		super('maxBuffer exceeded');
@@ -33,14 +36,7 @@ async function getStream(inputStream, options) {
 			reject(error);
 		};
 
-		pipeline(inputStream, stream, error => {
-			if (error) {
-				rejectPromise(error);
-				return;
-			}
-
-			resolve();
-		});
+		streamPipelinePromisified(inputStream, stream).then(resolve, rejectPromise);
 
 		stream.on('data', () => {
 			if (stream.getBufferedLength() > maxBuffer) {