Use apid.DB interface

api_test.go

diff --git a/api_test.go b/api_test.go
index 485ee29..0a544f7 100644
--- a/api_test.go
+++ b/api_test.go
@@ -20,7 +20,7 @@
 var _ = Describe("api", func() {
 
 	var tmpDir string
-	var db *sql.DB
+	var db apid.DB
 	var server *httptest.Server
 
 	BeforeSuite(func() {

init.go

diff --git a/init.go b/init.go
index 3733719..b0a45e8 100644
--- a/init.go
+++ b/init.go
@@ -1,7 +1,6 @@
 package apidVerifyApiKey
 
 import (
-	"database/sql"
 	"github.com/30x/apid"
 )
 
@@ -48,7 +47,7 @@
 	return nil
 }
 
-func createTables(db *sql.DB) {
+func createTables(db apid.DB) {
 	_, err := db.Exec(`
 CREATE TABLE api_product (
     id text,