print errors to stderr in cobra init boilerplate (spf13#774)

cobra/cmd/testdata/root.go.golden

@@ -47,10 +47,10 @@ to quickly create a Cobra application.`,
 // Execute adds all child commands to the root command and 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)
-  }
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
 }
 
 func init() {
@@ -78,7 +78,7 @@ func initConfig() {
     // Find home directory.
     home, err := homedir.Dir()
     if err != nil {
-      fmt.Println(err)
+      fmt.Fprintln(os.Stderr, err)
       os.Exit(1)
     }
 
@@ -91,7 +91,7 @@ func initConfig() {
 
   // If a config file is found, read it in.
   if err := viper.ReadInConfig(); err == nil {
-    fmt.Println("Using config file:", viper.ConfigFileUsed())
+    fmt.Fprintln(os.Stderr, "Using config file:", viper.ConfigFileUsed())
   }
 }