feat(helm): add helm upgrade command

cmd/helm/upgrade.go

+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+const upgradeDesc = `
+This command upgrades a release to a new version of a chart.
+
+The upgrade arguments must be a release and a chart. The chart
+argument can be a relative path to a packaged or unpackaged chart.
+`
+
+var upgradeCmd = &cobra.Command{
+	Use:   "upgrade [RELEASE] [CHART]",
+	Short: "upgrade a release",
+	Long:  upgradeDesc,
+	RunE:  runUpgrade,
+}
+
+func init() {
+	RootCommand.AddCommand(upgradeCmd)
+}
+
+func runUpgrade(cmd *cobra.Command, args []string) error {
+	fmt.Println("Coming Soon")
+	return nil
+}