fix: revert gin link. (#20)

README.md

@@ -33,7 +33,7 @@ import (
 	"time"
 
 	"gopkg.in/gin-contrib/cors.v1"
-	"gopkg.in/gin-gonic/gin.v1"
+	"github.com/gin-gonic/gin"
 )
 
 func main() {

config.go

@@ -3,7 +3,7 @@ package cors
 import (
 	"net/http"
 
-	"gopkg.in/gin-gonic/gin.v1"
+	"github.com/gin-gonic/gin"
 )
 
 type cors struct {

cors_test.go

@@ -7,8 +7,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/gin-gonic/gin"
 	"github.com/stretchr/testify/assert"
-	"gopkg.in/gin-gonic/gin.v1"
 )
 
 func init() {

examples/example.go

@@ -3,8 +3,8 @@ package main
 import (
 	"time"
 
+	"github.com/gin-gonic/gin"
 	"gopkg.in/gin-contrib/cors.v1"
-	"gopkg.in/gin-gonic/gin.v1"
 )
 
 func main() {