/**
  * Update the specified resource in storage.
  *
  * @param  int  $id
  *
  * @return Response
  */
 public function update($id, Request $request)
 {
     $this->validate($request, ['nombre_de_facultad' => 'required', 'descripcion' => 'required']);
     $sistemapg = Sistemapg::findOrFail($id);
     $sistemapg->update($request->all());
     Session::flash('flash_message', 'Sistemapg updated!');
     return redirect('admin/sistemapg');
 }