fix(index): stop type coercion

[Fdawgs]

The global isFinite() attempts type coercion whilst Number.isFinite() does not. The params for this function are expected to be numbers, so we shouldn't be doing any type coercion:

csrf/index.js

Lines 13 to 22 in 631884d

	/**
	* Token generation/verification class.
	*
	* @param {object} [options]
	* @param {number} [options.saltLength=8] The string length of the salt
	* @param {number} [options.secretLength=18] The byte length of the secret key
	* @param {number} [options.validity=0] The maximum milliseconds of validity of this token. 0 disables the check.
	* @param {boolean} [options.userInfo=false] Require userInfo on create() and verify()
	* @public
	*/

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct