lint also tests folder

tests/application.js

@@ -2,26 +2,26 @@ import electron from "electron";
 import { Application } from "spectron";
 
 const startApplication = function() {
-  this.timeout(30000);
-  this.app = new Application({
-    path: electron,
-    args: ["."],
-    startTimeout: 30000,
-    waitTimeout: 30000,
-    quitTimeout: 10000
-  });
-  return this.app.start();
+	this.timeout(30000);
+	this.app = new Application({
+		path: electron,
+		args: ["."],
+		startTimeout: 30000,
+		waitTimeout: 30000,
+		quitTimeout: 10000
+	});
+	return this.app.start();
 };
 
 const stopApplication = function() {
-  this.timeout(30000);
-  if (this.app && this.app.isRunning()) {
-    return this.app.stop();
-  }
-  return undefined;
+	this.timeout(30000);
+	if (this.app && this.app.isRunning()) {
+		return this.app.stop();
+	}
+	return undefined;
 };
 
 export {
-  startApplication,
-  stopApplication
+	startApplication,
+	stopApplication
 };