add mysql store

Author: LyricTian

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2018 Golang Session
+Copyright (c) 2018 Lyric
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,2 +1,93 @@
-# mysql
-MySQL store for Session.
+# MySQL store for [Session](https://github.com/go-session/session)
+
+[![ReportCard][reportcard-image]][reportcard-url] [![GoDoc][godoc-image]][godoc-url] [![License][license-image]][license-url]
+
+## Quick Start
+
+### Download and install
+
+```bash
+$ go get -u -v github.com/go-session/mysql
+```
+
+### Create file `server.go`
+
+```go
+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/go-session/mysql"
+	"github.com/go-session/session"
+	_ "github.com/go-sql-driver/mysql"
+)
+
+func main() {
+	dsn := "root:123456@tcp(127.0.0.1:3306)/myapp_test?charset=utf8"
+	session.InitManager(
+		session.SetStore(mysql.NewStore(mysql.NewConfig(dsn), "", 0)),
+	)
+
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		store, err := session.Start(context.Background(), w, r)
+		if err != nil {
+			fmt.Fprint(w, err)
+			return
+		}
+
+		store.Set("foo", "bar")
+		err = store.Save()
+		if err != nil {
+			fmt.Fprint(w, err)
+			return
+		}
+
+		http.Redirect(w, r, "/foo", 302)
+	})
+
+	http.HandleFunc("/foo", func(w http.ResponseWriter, r *http.Request) {
+		store, err := session.Start(context.Background(), w, r)
+		if err != nil {
+			fmt.Fprint(w, err)
+			return
+		}
+
+		foo, ok := store.Get("foo")
+		if ok {
+			fmt.Fprintf(w, "foo:%s", foo)
+			return
+		}
+		fmt.Fprint(w, "does not exist")
+	})
+
+	http.ListenAndServe(":8080", nil)
+}
+
+```
+
+### Build and run
+
+```bash
+$ go build server.go
+$ ./server
+```
+
+### Open in your web browser
+
+<http://localhost:8080>
+
+    foo:bar
+
+## MIT License
+
+    Copyright (c) 2018 Lyric
+
+[reportcard-url]: https://goreportcard.com/report/github.com/go-session/mongo
+[reportcard-image]: https://goreportcard.com/badge/github.com/go-session/mongo
+[godoc-url]: https://godoc.org/github.com/go-session/mongo
+[godoc-image]: https://godoc.org/github.com/go-session/mongo?status.svg
+[license-url]: http://opensource.org/licenses/MIT
+[license-image]: https://img.shields.io/npm/l/express.svg