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