Initial phantom postgres realization
Make default postgres params
Create environment variable PG_POOL_CONFIG
Add default pg_pool config for test and travis
Crazy modification in test bootstraping in makefile

When you make `application:start(pg_pool)` system reports
that `pg_pool.app` is not exists. But this is strange since
`pg_pool.app` placing at `lib/pg_pool/ebin` -- seems as a rebar bug.

BTW we could manually add `lib/pg_pool/ebin` (and other) via `-pa`
option to erlang emulator. However it's seems a little bit tricky -- as
far as eunit starts from rebar and rebar didn't allow to tune erlang
from command line We need to supply arguments via environment
(ERL_AFLAGS).
Update travis config
Ping postgres test
Fix travis CREATE DATABASE and others
Merge branch 'phantom_postgres'