[pg_hba.conf] publish own Python application using PostgreSQL

I have my own Python application using a PostgreSQL database over
SQLAlchemy.

Currently I pack the application in a deb-file.
After installation (on a fresh system! Ubuntu 14.04.2) it doesn't run
because of some PostgreSQL-settings.
Of course I understand why and I know (a little bit) which settings I
have to do to make it run.

But the point is I don't want to plague my user to do that.

How could this be solved?
How can I release a application using a local PostgreSQL-database.
I am not sure if the modifications I do are correct or elegant (see
below).

These are the modification I have to do to make my application run with
the connetion string "postgres://puser(at)localhost/FoobarTest".

The settings are about
the /etc/postgresql/9.3/main/pg_hba.conf file.
There I change this line
host all all 127.0.0.1/32 md5
to
host all all 127.0.0.1/32 trust

I have to create a user without a password (beside the admin/postgres),
too.