Added testGetUser() that reads a single user.
Added testGetUser() that reads a single user.

HiTask/intercom-php,artarmstrong/intercom-php,kmuenze/intercom-php,luisefabian/intercom-php,JaapRood/intercom-php,gnudle/intercom-php,reinoudvansanten/intercom-php,xpelliarmus/intercom-php,wakeless-net/intercom-php