Crash when input jar does not have manifest

[Col-E]

Cause: https://github.com/netindev/scuti/blob/master/scuti-core/src/main/java/tk/netindev/scuti/core/Scuti.java#L109

this.outputStream = new JarOutputStream(new FileOutputStream(this.configuration.getOutput()), null);

JarOutputStream's second parameter cannot be null.