Installing zammad from a source

Yeah, I have checked multiple times, I am using the copy of database.yml inside the config directory with the content I have shared above. But even for the file config/database/database.yml the syntax seems right.

# this is a database config sample for zammad ready to use with a postgresql db
# copy or symlink this file to config/database.yml to use it

default: &default
  # For details on connection pooling, see Rails configuration guide
  # http://guides.rubyonrails.org/configuring.html#database-pooling
  pool: 50
  encoding: utf8

  ##### postgresql config #####

  adapter: postgresql
   # username: zammad
   # password: 'mypass'

  # If the database server is not on localhost, you can set hostname and port:
  # host:
  # port:

  #### mysql config #####

  # adapter: mysql2
  # username: zammad
  # password: <Password>

  # If the database server is not on localhost, you can set hostname and port:
  # host:
  # port:

production:
  <<: *default
  database: zammad_production

development:
  <<: *default
  database: zammad_development

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: zammad_test