To lower case object fix

Fixes error calling toLowerCase() on an object resulting in an error:
```
Object has no method 'toLowerCase'
```

This is a fix for the issue I created here: https://github.com/balderdashy/sails-postgresql/issues/80

Please let me know when this is merged to the version on NPM as this is causing an error in an app I plan on deploying to Heroku and I'd like to use the NPM version of the module (and not my fork).