Modifies the 'string time to timestamp' behat trasformation to use
userdate() instead of date(). The userdate() method is generally used
throught Moodle for constructing formatted date strings and this change
will provide more consistency and prevent any potential behat failures.
Therefore, if the date format is defined in the given trasformation, it
has to be strftime compatible. Example:
'I should see "##tomorrow noon##%A, %d %B %Y, %I:%M %p##"'