replaced hardwired path to travis build dir with placeholder. annotated what's going on in comments.
added in-place token substitution for travis build path in behat config file.
fixed path to behat.yml file.
another stab at injecting the drupal root path into the behat configuration at runtime.
Merge pull request #21 from stopfstedt/unkludge-travis-profile

Unkludge travis profile