Fix failing test (#155)

Author: LitoMore

package.json

@@ -13,7 +13,7 @@
 		"node": ">=8"
 	},
 	"scripts": {
-		"test": "xo && ava --timeout=20s"
+		"test": "xo && ava --timeout=20s -s"
 	},
 	"files": [
 		"index.js",

test/notify.js

@@ -21,7 +21,7 @@ function Control(shouldNotifyInNpmScript) {
 const setupTest = isNpmReturnValue => {
 	['..', 'is-npm'].forEach(clearModule);
 	process.stdout.isTTY = true;
-	mock('is-npm', isNpmReturnValue || false);
+	mock('is-npm', {isNpm: isNpmReturnValue || false});
 	const updateNotifier = require('..');
 	util.inherits(Control, updateNotifier.UpdateNotifier);
 };
@@ -70,7 +70,7 @@ test('shouldNotifyInNpmScript should default to false', t => {
 	t.not(stripAnsi(errorLogs).indexOf('Update available'), -1);
 });
 
-test.failing('suppress output when running as npm script', t => {
+test('suppress output when running as npm script', t => {
 	setupTest(true);
 	const notifier = new Control();
 	notifier.notify({defer: false});