public function postSurvey(Request $request)
 {
     $this->validate($request, ['email' => 'required|email']);
     $survey = Survey::firstOrCreate(['email' => $request->input('email')]);
     $request->session()->put('survey', $survey);
     return redirect()->action('SurveyController@getSurveyStep', ['step' => 1]);
 }