Use envvars for stdlib tests

stdlib/stdlibutil_test.go

@@ -4,12 +4,13 @@ package stdlib_test
 
 import (
 	"database/sql"
+	"os"
 	"testing"
 )
 
 // this file contains utility functions for tests that differ between versions.
 func openDB(t *testing.T) *sql.DB {
-	db, err := sql.Open("pgx", "postgres://pgx_md5:secret@127.0.0.1:5432/pgx_test")
+	db, err := sql.Open("pgx", os.Getenv("PGX_TEST_DATABASE"))
 	if err != nil {
 		t.Fatalf("sql.Open failed: %v", err)
 	}