Added option for Gulp logging

Typically Gulp plugins suppress the output of the native module and add an option to log the output. Basically:

```js
.pipe(bless({
  log: true
}));
```

Gives the option of keeping the command line clean.
Generally yes but for options I'm making it specific to avoid people getting true when entering 1, !0, !null, etc. Check this out for some interesting reading: http://dorey.github.io/JavaScript-Equality-Table/