[Nightmare] Load blank page when starting nightmare so that the .evaluate function will work if _failed/saveScreenshot is triggered before a page is loaded by the user (codeceptjs#938)

Author: reubenmiller

lib/helper/Nightmare.js

@@ -231,6 +231,7 @@ class Nightmare extends Helper {
       this.browser = this.Nightmare(this.options);
       await this.browser;
     }
+    await this.browser.goto('about:blank'); // Load a blank page so .saveScreenshot (/evaluate) will work
     this.isRunning = true;
     this.browser.on('dom-ready', () => this._injectClientScripts());
     this.browser.on('did-start-loading', () => this._injectClientScripts());