Update module gorilla/sessions to v1.2.0

Author: renovate-bot

go.mod

@@ -30,7 +30,7 @@ require (
 	github.com/gorilla/mux v1.7.3
 	github.com/gorilla/schema v1.1.0
 	github.com/gorilla/securecookie v1.1.1
-	github.com/gorilla/sessions v1.1.3
+	github.com/gorilla/sessions v1.2.0
 	github.com/imkira/go-interpol v1.1.0 // indirect
 	github.com/jinzhu/gorm v1.9.12
 	github.com/joho/godotenv v1.3.0