Add 'config' command to start interacting with zb configuration

Make it easier to verify what configuration 'zb' is using.

Author: msp301

cmd/config.go

@@ -0,0 +1,22 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+var configCmd = &cobra.Command{
+	Use:   "config",
+	Short: "Get and set configuration options",
+	Run: func(cmd *cobra.Command, args []string) {
+		jsonStr, _ := json.MarshalIndent(viper.AllSettings(), "", "  ")
+		fmt.Println(string(jsonStr))
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(configCmd)
+}