Add md5 password authentication for Postgres

Postgres image, by default, configures host-based authentication (pg_hba.conf) to trust from everywhere. So, no password is needed to connect to the database. Change this to use md5 password authentication.

Author: chunky56

Dockerfile

@@ -1,3 +1,5 @@
 FROM postgres:9.4
 
 COPY init/ /docker-entrypoint-initdb.d
+
+RUN echo "host all all 0.0.0.0/0 md5" > /var/lib/postgresql/data/pg_hba.conf