Binding HostName to Deployment slot uses name incorrectly. (#250)

* Fixed an issue with the incorrect deployment slot name being used when binding hostnames.

* Update LICENSE.txt

LICENSE.txt

@@ -19,3 +19,4 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
+

src/ResourceManagement/AppService/HostNameBindingImpl.cs

@@ -103,8 +103,8 @@ public HostNameBindingImpl<FluentT, FluentImplT, DefAfterRegionT, DefAfterGroupT
         ///GENMHASH:32A8B56FE180FA4429482D706189DEA2:9462BB1488F8B757A53382E31550B2EC
         public async Task<IHostNameBinding> CreateAsync(CancellationToken cancellationToken = default(CancellationToken))
         {
-            var hostNameBindingInner = parent is IDeploymentSlot
-                    ? await parent.Manager.Inner.WebApps.CreateOrUpdateHostNameBindingSlotAsync(parent.ResourceGroupName, ((IDeploymentSlot)parent).Parent.Name, name, Inner, parent.Name)
+            var hostNameBindingInner = parent is IDeploymentSlot deploymentSlot
+                    ? await parent.Manager.Inner.WebApps.CreateOrUpdateHostNameBindingSlotAsync(parent.ResourceGroupName, deploymentSlot.Parent.Name, name, Inner, deploymentSlot.Name)
                     : await parent.Manager.Inner.WebApps.CreateOrUpdateHostNameBindingAsync(parent.ResourceGroupName, parent.Name, name, Inner);
             SetInner(hostNameBindingInner);