public static async Task<ResponsavelAluno> insertResponsavelAluno(string responsavelId, string alunoId)
 {
     ResponsavelAluno responsavelAluno = new ResponsavelAluno { ResponsavelId = responsavelId, AlunoId = alunoId };
     await App.MobileService.GetTable<ResponsavelAluno>().InsertAsync(responsavelAluno);
     return responsavelAluno;
 }
 public static async void updateResponsavelAluno(ResponsavelAluno responsavelAluno)
 {
     await App.MobileService.GetTable<ResponsavelAluno>().UpdateAsync(responsavelAluno);
 }