public void ReserveOfferTest()
{
ReserveOfferDto dto = new ReserveOfferDto()
{
Username = "******",
OfferId = 2
};
IHttpActionResult result = _controller.ReserveOffer(dto);
var contentResult = result as OkNegotiatedContentResult <bool>;
Offer o = _context.Offers.FirstOrDefault(x => x.Id == dto.OfferId);
Assert.IsNotNull(o);
Assert.AreEqual(true, o.IsBooked);
Assert.IsTrue(o.Customer.Username.Equals("jablonskim"));
}