Remove number argument

Use `getPort({port: <number>})` instead.

index.js

@@ -14,12 +14,6 @@ const isAvailable = options => new Promise((resolve, reject) => {
 });
 
 const getPort = (options = {}) => new Promise((resolve, reject) => {
-	// For backwards compatibility with number-only input
-	// TODO: Remove this in the next major version
-	if (typeof options === 'number') {
-		options = {port: options};
-	}
-
 	if (typeof options.port === 'number') {
 		options.port = [options.port];
 	}
@@ -34,5 +28,5 @@ const getPort = (options = {}) => new Promise((resolve, reject) => {
 });
 
 module.exports = options => options ?
-	getPort(options).catch(() => getPort(0)) :
-	getPort(0);
+	getPort(options).catch(() => getPort({port: 0})) :
+	getPort({port: 0});

test.js

@@ -16,7 +16,7 @@ test('port can be bound when promise resolves', async t => {
 
 test('preferred port', async t => {
 	const desiredPort = 8080;
-	const port = await m(desiredPort);
+	const port = await m({port: desiredPort});
 
 	t.is(port, desiredPort);
 });
@@ -28,7 +28,7 @@ test('preferred port unavailable', async t => {
 	const server = net.createServer();
 	await pify(server.listen.bind(server))(desiredPort);
 
-	const port = await m(desiredPort);
+	const port = await m({port: desiredPort});
 	t.is(typeof port, 'number');
 	t.true(port > 0);
 	t.not(port, desiredPort);