Removed Postgre Close test since the pgx implementation of Close() doesn't return an error,

Removed Storage.Close()'s return method since the pgx implementation of Close() doesn't return an error,
Removed Config.maxIdleConns since pgx implementation doesn't support setting a maximum number of idle connections

postgres/postgres_test.go

@@ -1,6 +1,7 @@
 package postgres
 
 import (
+	"context"
 	"database/sql"
 	"os"
 	"testing"
@@ -133,7 +134,7 @@ func Test_Postgres_GC(t *testing.T) {
 	utils.AssertEqual(t, nil, err)
 
 	testStore.gc(time.Now())
-	row := testStore.db.QueryRow(testStore.sqlSelect, "john")
+	row := testStore.db.QueryRow(context.Background(), testStore.sqlSelect, "john")
 	err = row.Scan(nil, nil)
 	utils.AssertEqual(t, sql.ErrNoRows, err)
 
@@ -173,7 +174,3 @@ func Test_SslRequiredMode(t *testing.T) {
 		SslMode:  "require",
 	})
 }
-
-func Test_Postgres_Close(t *testing.T) {
-	utils.AssertEqual(t, nil, testStore.Close())
-}