Merge branch 'rel/2.0.0-preview1' into dev

src/Microsoft.AspNetCore.Server.IntegrationTesting/Deployers/IISExpressDeployer.cs

@@ -301,7 +301,7 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
 
             // If by this point, the host process is still running (somehow), throw an error.
             // A test failure is better than a silent hang and unknown failure later on
-            if (!_hostProcess.HasExited)
+            if (_hostProcess != null && !_hostProcess.HasExited)
             {
                 throw new Exception($"iisexpress Process {_hostProcess.Id} failed to shutdown");
             }