Gbq upgrade
This adds support for service account authorization to Google Big Query API + some informative messages on std out.

GBQ can be used with Python 3. In RTBHouse we are doing this since may. It works perfectly with this pandas upgrade.

this was done in 0.17.0 released on October 

http://pandas.pydata.org/pandas-docs/stable/whatsnew.html#google-bigquery-enhancements

so pls rebase on master

you can submit other enhancements if you wish - 
 I will rebase :) sorry
but I do not see any support for google service account auth in master now.
This is usable when working from remote host Jupyter/iPython web notebooks and one can not authorize to google by web request
 iirc we have an issue for the service account
if u can find one pls xref it (and of course impl welcome as well)
 ok, I found this 
https://github.com/pydata/pandas/issues/8489
I'll push my patch for that
