Process exit listeners are leaking

[qtiki]

Process exit listeners aren't removed properly when the child process exits. This leads to a node warning once you start and stop the offline DynamoDB more than 10 times:

(node:9960) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 exit listeners added. Use emitter.setMaxListeners() to increase limit

The listener seems to be registered here:

dynamodb-local/index.js

Line 84 in 355365e

process.on('exit', function() {

[qtiki]

Here's code to reproduce:

const db = require('dynamodb-local');

async function test() {
	for (let i = 0; i < 11; i++) {
		await db.launch(8000, null, ['-inMemory'], true);
		db.stop(8000);
	}
}

test();