[ci]: use PostgreSQL 10 and some 9.5 on Travis
[ci]: use PostgreSQL 10 and some 9.5 on Travis

bruceadams/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter