public void PostUploadImage_ShouldUpload()
{
var expectedLink = "link";
var file = Substitute.For <IFormFile>();
var fileStreamMock = new MemoryStream();
file.OpenReadStream().Returns(fileStreamMock);
_imgurGateway.UploadImage(fileStreamMock).Returns(expectedLink);
var results = _controller.PostUploadImage(file).Result;
Assert.AreEqual(expectedLink, results);
}