Set application exit code

Author: gitfool

src/GitVersionExe.Tests/ExecCmdLineArgumentTest.cs

@@ -98,7 +98,7 @@ public void WorkingDirectoryDoesNotExistCrashesWithInformativeMessage()
                 args,
                 PathHelper.GetCurrentDirectory());
 
-            exitCode.ShouldBe(0);
+            exitCode.ShouldNotBe(0);
             var outputString = output.ToString();
             outputString.ShouldContain($"The working directory '{workingDirectory}' does not exist.", () => outputString);
         }

src/GitVersionExe/GitVersionApp.cs

@@ -27,11 +27,12 @@ public Task StartAsync(CancellationToken cancellationToken)
             {
                 var arguments = options.Value;
                 log.Verbosity = arguments.Verbosity;
-                gitVersionExecutor.Execute(arguments);
+                System.Environment.ExitCode = gitVersionExecutor.Execute(arguments);
             }
             catch (Exception exception)
             {
                 Console.Error.WriteLine(exception.Message);
+                System.Environment.ExitCode = 1;
             }
 
             applicationLifetime.StopApplication();