mod(cli): remove version command and replace with flag instead

cmd/root.go

@@ -8,7 +8,10 @@ import (
 	"github.com/spf13/viper"
 )
 
+const VERSION string = "0.1"
+
 var (
+	version bool
 	dry_run bool
 	rootCmd = &cobra.Command{
 		Use:   "gitw",
@@ -24,6 +27,9 @@ func Execute() error {
 
 func init() {
 	cobra.OnInitialize(initConfig)
+	// version flag
+	rootCmd.Flags().BoolVarP(&version, "version", "v", false, "Print version of gitwarrior")
+	rootCmd.Version = VERSION
 }
 
 func initConfig() {

cmd/version.go

@@ -1,20 +0,0 @@
-package cmd
-
-import (
-	"fmt"
-
-	"github.com/spf13/cobra"
-)
-
-func init() {
-	rootCmd.AddCommand(versionCmd)
-}
-
-var versionCmd = &cobra.Command{
-	Use:   "version",
-	Short: "Print the version of gitwarrior",
-	Long:  `All software has versions. This is gitwarrior's`,
-	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Println("v0.1")
-	},
-}