Incomplete solution to node v10 compatibility

[tmcw]

This fails 3 tests in Node v10 - I can't quite find a way to keep cp-file's promise that it'll only create a directory for output if the output can be read from the stream - that requires waiting a tick between readable and pipe and that breaks behavior much more (instead of failing 3 tests, master fails 15.

Unfortunately the Node v10 changelog only says

The 'readable' event is now always deferred with nextTick.

Which doesn't clearly point to why this would break.

[schnittstabil]

A more stripped-down test (without cp-file and pipe):

const fs = require('fs');
const read = fs.createReadStream(__filename);

new Promise((resolve, reject) => {
    read.on('error', err => {
        reject(err);
    });
    read.on('readable', () => {
        resolve(read);
    });
}).then(readable => {
    console.log('ok');
    readable.on('data', chunk => {
        console.log('data');
    });
}).catch(err => console.error(err));

Output:

# node < v10.0.0
ok
data

# node v10.0.0
ok

[tmcw]

That looks like it could be a node core bug: filed an issue upstream: nodejs/node#20520

[tmcw]

Closing in favor of #26