Use helper for logging command error

cmd/root.go

@@ -15,9 +15,7 @@
 package cmd
 
 import (
-	"fmt"
-	"os"
-
+	"github.com/jjdekker/ponder/helpers"
 	"github.com/spf13/cobra"
 )
 
@@ -37,10 +35,8 @@ other PDF files to be part of your song book.`,
 // Execute adds all child commands to the root command sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.
 func Execute() {
-	if err := RootCmd.Execute(); err != nil {
-		fmt.Println(err)
-		os.Exit(-1)
-	}
+	err := RootCmd.Execute()
+	helpers.Check(err, "Command returned an error")
 }
 
 func init() {