So I found this article which said:

 $ sudo -u postgres psql

 postgres=> alter user postgres password 'apassword';
 postgres=> create user your-user createdb createuser password 'passwd';
 postgres=> create database your-db-name owner your-user;
 postgres=> \q

Note: to enable password logins for the ‘postgres’ admin account, edit: /etc/postgresql/9.4/main/pg_hba.conf and after this line:

local   all             postgres                                peer

Add this line:

local   all             postgres                                md5