Access to the BigQuery (and any of the additional tools on Google Cloud Platform) requires some additional packages to authenticate the request.
Simply add the following to your requirements.txt.
httplib2==0.11.3
google-api-python-client>=1.5.0, <1.6.0
oauth2client>=2.0.2, <2.1.0
PyOpenSSL
pandas-gbq
google-cloud-storage
Now add the following to packages.txt.
libgcrypt=1.8.3-r0
libxslt-dev
g++
libstdc++
And you should be good to go!