Method: https://login.pac-metrix.com/api/api/Authentication (GET)
Usage:
Use this method to authenticate using a username and password. If successful you will receive an ApiKey which is good for 48 hours. All other API calls require this ApiKey in order to function.
Inputs:
stringuserid The login (user id) of a pre-existing user in the PAC Metrix system.
stringpassword The password supplied by this user.
Returns:
string The ApiKey that will be passed to all other Api calls.