Gofakeit v6. Now supports concurrency and crypto/rand

The new v6 release now supports the ability to have localized rand that allows for concurrent generating of random data. Crypto/rand has now been integrated as well as if you have a custom rand that fulfills the math/rand source64 interface you can use it with gofakeit. Let me know your thoughts.

https://github.com/brianvoe/gofakeit