/// <summary>
 /// Updates waiter info.
 /// </summary>
 /// <param name="id"></param>
 /// <param name="waiter"></param>
 /// <returns></returns>
 public async Task<bool> UpdateWaiter(int id,Waiter waiter)
 {
     var _waiter = new Waiter
     {
         Id=waiter.Id,
         FirstName = waiter.FirstName,
         LastName = waiter.LastName,
         Password = waiter.Password
     };
     var response = await client.PutAsJsonAsync(uriWaiters+"/"+ id, _waiter);
     if (response.IsSuccessStatusCode)
     {
         return true;
     }
     return false;
 }
 /// <summary>
 /// Adds waiter to database.
 /// </summary>
 /// <param name="waiter"></param>
 /// <returns></returns>
 public async Task<bool> AddWaiter(Waiter waiter)
 {
     var _waiter = new Waiter
     {
         FirstName= waiter.FirstName,
         LastName = waiter.LastName,
         Password = waiter.Password
     };
     HttpResponseMessage response = await client.PostAsJsonAsync(uriWaiters, _waiter);
     if (response.IsSuccessStatusCode)
     {
         return true;
     }
     return false;
 }