Add host and port to DB connection config

db/connect.rb

 DB =
   Sequel.connect(
     adapter: :postgres,
+    host: ENV['DB_HOST'] || 'localhost',
     database: ENV['DB_DATABASE'],
     user: ENV['DB_USERNAME'],
     password: ENV['DB_PASSWORD'],
+    port: ENV['DB_PORT'] || 5432,
     logger: ENV['APP_ENV'] == 'development' ? Logger.new('db/log') : nil
   )