In data.json file, the Faker's formatter's options seems to not accept arrays

[RedLucas]

I know there's not many use-cases for this which is probably for why we missed it. If you were to try to use Faker.randomElement(), it uses an array as a parameter. This gives me
Fatal error: Uncaught TypeError: Argument 1 passed to Faker\Provider\Base::randomElements() must be of the type array, string given

I understand why this is happening. Later in the stack trace it's showing me a Faker\Provider\Base::randomElement('array('top', 'left', 'right')'). So I believe that there's some code somewhere that's wrapping these parameters in quotes.... If I get some time I'll try to find it myself.

If there's a rational reason for why this is happening, perhaps we could enforce the newer [] array syntax? So we could not wrap it in quotes (make it a string) if the parameter starts with a '['?

[RedLucas]

Delivered a fix at #5