added version command

Signed-off-by: Andreas Ulm <andreas.ulm@root360.de>

cmd/version.go

@@ -0,0 +1,35 @@
+// Copyright © 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package cmd
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// Version holds the current Gitea version
+var Version = "0.1.0-dev"
+
+// Tags holds the build tags used
+var Tags = ""
+
+// versionCmd represents the version command
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Print version",
+	Long: ``,
+	Run: func(cmd *cobra.Command, args []string) {
+		if len(Tags) > 0 {
+			Version += " built with: " + strings.Replace(Tags, " ", ", ", -1)
+		}
+		fmt.Println("Version " + Version)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(versionCmd)
+}