Made PostgreSQL 9.4 the main version in CircleCI
Made PostgreSQL 9.4 the main version in CircleCI

Made 9.4 the main version in a previous commit, but forgot to update the
CircleCI config.

realazthat/pg8000,realazthat/pg8000,kaniini/pg8000,kaniini/pg8000,tlocke/pg8000