Update warning message, for GitTools#313

Author: serra

src/GitVersionExe.Tests/ArgumentParserTests.cs

@@ -116,7 +116,7 @@ public void Username_and_Password_can_be_parsed()
     public void Unknown_output_should_throw()
     {
         var exception = Assert.Throws<WarningException>(() => ArgumentParser.ParseArguments("targetDirectoryPath -output invalid_value"));
-        exception.Message.ShouldBe("Value 'invalid_value' cannot be parsed as output type, please use 'json' or 'buildserver'");
+        exception.Message.ShouldBe("Value 'invalid_value' cannot be parsed as output type, please use 'json', 'props' or 'buildserver'");
     }
 
     [Test]

src/GitVersionExe/ArgumentParser.cs

@@ -220,7 +220,7 @@ public static Arguments ParseArguments(List<string> commandLineArguments)
                     OutputType outputType;
                     if (!Enum.TryParse(value, true, out outputType))
                     {
-                        throw new WarningException(string.Format("Value '{0}' cannot be parsed as output type, please use 'json' or 'buildserver'", value));
+                        throw new WarningException(string.Format("Value '{0}' cannot be parsed as output type, please use 'json', 'props' or 'buildserver'", value));
                     }
 
                     arguments.Output = outputType;