remove pipeline() chain

it cannot be chained afaict

src/hush.js

@@ -6,7 +6,6 @@ const assert = require('assert'),
     debug = require('debug')('box:hush'),
     fs = require('fs'),
     ProgressStream = require('./progress-stream.js'),
-    stream = require('stream'),
     TransformStream = require('stream').Transform;
 
 class EncryptStream extends TransformStream {
@@ -181,35 +180,6 @@ function createReadStream(sourceFile, encryption) {
     }
 }
 
-function createWriteStream(destFile, encryption) {
-    assert.strictEqual(typeof destFile, 'string');
-    assert.strictEqual(typeof encryption, 'object');
-
-    const destStream = fs.createWriteStream(destFile);
-    const ps = new ProgressStream({ interval: 10000 }); // display a progress every 10 seconds
-
-    const streams = [ ps ];
-
-    if (encryption) {
-        const decryptStream = new DecryptStream(encryption);
-        streams.push(decryptStream);
-    }
-
-    streams.push(destStream);
-
-    stream.pipeline(streams, function (error) {
-        if (error) {
-            debug(`createWriteStream: write stream error ${destFile}. %o`, error);
-            ps.emit('error', new BoxError(BoxError.FS_ERROR, `Write error ${destFile}: ${error.message}`));
-        } else {
-            debug(`createWriteStream: ${destFile} done`);
-            return ps.emit('done');
-        }
-    });
-
-    return ps;
-}
-
 exports = module.exports = {
     EncryptStream,
     DecryptStream,
@@ -218,5 +188,4 @@ exports = module.exports = {
     decryptFilePath,
 
     createReadStream,
-    createWriteStream
 };