Fixed #2 deletePush

Check if parameters is 'null', if so, don't send parameters (payload)
Please don't use hard tabs. Github sets them to 8 spaces, rather than 4 like in most text editors, which makes the display ugly, and on many projects, people will take a huge amount of offense if hard and soft tabs are mixed. Just make sure that your text editor is set to autodetect, or that you chose manually based on what the project has.