public function postSignup(Request $request)
 {
     $this->validate($request, ['firstname' => 'required|alpha|max:20', 'lastname' => 'alpha|max:20', 'email' => 'required|unique:students|email|max:255', 'password' => 'required|min:8']);
     User::create(['first_name' => $request->input('firstname'), 'last_name' => $request->input('lastname'), 'email' => $request->input('email'), 'password' => bcrypt($request->input('password'))]);
     return redirect()->route('home')->with('info', 'Your account has been created and you can now Sign In.');
 }