up: avoids user and password for local tests

The `require` now is local avoiding require unnecessary driver.

spec/support/database.rb

@@ -1,30 +1,24 @@
 # frozen_string_literal: true
 
-require 'mysql2'
-require 'pg'
-
 ENV['DB'] ||= 'mysql'
 
-conn_params = {
-  database: :rating_test,
-  host: '127.0.0.1',
-}
+conn_params = { database: :rating_test, host: '127.0.0.1' }
 
 case ENV.fetch('DB', nil)
 when 'mysql'
-  client = Mysql2::Client.new(host: '127.0.0.1', username: :root)
+  require 'mysql2'
+
+  client = Mysql2::Client.new(host: conn_params[:host], username: :root)
+
   conn_params[:adapter] = :mysql2
   conn_params[:username] = :root
 when 'postgres'
-  ENV['POSTGRES_USER'] ||= 'rating_user'
-  client = PG::Connection.new(host: '127.0.0.1', user: ENV.fetch('POSTGRES_USER', nil),
-    password: ENV.fetch('POSTGRES_PASSWORD', nil)
-  )
-  conn_params.merge!(
-    adapter: :postgresql,
-    username: ENV.fetch('POSTGRES_USER', nil),
-    password: ENV.fetch('POSTGRES_PASSWORD', nil)
-  )
+  require 'pg'
+
+  client = PG::Connection.new(host: conn_params[:host], user: :postgres)
+
+  conn_params[:adapter] = :postgresql
+  conn_params[:username] = :postgres
 end
 
 client.query('DROP DATABASE IF EXISTS rating_test;')