update gf version

go.mod

@@ -1,3 +1,5 @@
 module gtoken
 
-require github.com/gogf/gf v1.7.1
+require github.com/gogf/gf v1.8.3
+
+go 1.13

go.sum

@@ -1,2 +1,3 @@
 github.com/gogf/gf v1.7.1 h1:LECdt4UwVFpCGoWUk56dNFEHG9JxeKi34eOIdgFBbOg=
 github.com/gogf/gf v1.7.1/go.mod h1:witsoQr7PSjWHK2T1lOa1EKSFIs31QF0T8/+ITaJoho=
+github.com/gogf/gf v1.8.3/go.mod h1:qJRcq0s3RskjJIZKsSHjZkpxw91rd0EAh+4CUbawbXQ=