Weak Random Number Generator for Auth Tokens

https://github.com/joola/joola/blob/a534c3dca1a0deaec99c192978e61a35dd3a9069/lib/common/index.js#L90-L98 `Math.random()` is not sufficient for cryptographic purposes (such as authentication tokens). An example replacement that uses `window.crypto.getRandomValues()` is available here: https://github.com/resonantcore/lib/blob/9362480647b304aee6819ea94a18409241e79378/js/diceware/diceware.js#L60-L94 Further information: https://media.blackhat.com/us-13/US-13-Soeder-Black-Box-Assessment-of-Pseudorandom-Algorithms-WP.pdf