MsDeploy / WebDeploy plugin  #145

Task should inherit from ExternalProcessTaskBase. It should be implemented in a similar way as for example SqlCmdTask

We should discuss if tasks should be implmented as plugin or added directly to FlubuCore.

Until plugin is not implemented RunProgramTask can be used instead.

      context.CreateTarget("MsDeploy")
            .AddTask(x => x.RunProgramTask("MsDeploy.Exe")
                .WithArguments("Put desired args here."));