Moodle-Behat-Extension has been updated to use Behat 3.0.15 (MDL-46891)
We tried to keep BC as much as possible, but there are few cases which were not BC, please refer https://docs.moodle.org/dev/User_talk:Rajesh_Taneja#Migrating_from_Behat_2.5_to_3.x_in_Moodle for more information.