Octal literals are not allowed in strict mode

[WilliamHuey]

In the index.js, of this module, the octal literal is causing an error in 'strict' mode. I encounter this error when using babel and webpack to compile js output.

If all the '\033' were replaced with the hex equivalent, '\x1B', as shown in this repository: stevenvachon/cli-clear@e6458ee, the error will go away.

Thanks. 😃