Atomic option for the Upgrade step [#64]

internal/run/upgrade.go

@@ -18,6 +18,7 @@ type Upgrade struct {
 	ReuseValues  bool
 	Timeout      string
 	Force        bool
+	Atomic       bool
 
 	cmd cmd
 }
@@ -65,6 +66,9 @@ func (u *Upgrade) Prepare(cfg Config) error {
 	if u.Force {
 		args = append(args, "--force")
 	}
+	if u.Atomic {
+		args = append(args, "--atomic")
+	}
 	if u.Values != "" {
 		args = append(args, "--set", u.Values)
 	}

internal/run/upgrade_test.go

@@ -100,6 +100,7 @@ func (suite *UpgradeTestSuite) TestPrepareWithUpgradeFlags() {
 		ReuseValues:  true,
 		Timeout:      "sit_in_the_corner",
 		Force:        true,
+		Atomic:       true,
 	}
 
 	cfg := Config{}
@@ -113,6 +114,7 @@ func (suite *UpgradeTestSuite) TestPrepareWithUpgradeFlags() {
 			"--reuse-values",
 			"--timeout", "sit_in_the_corner",
 			"--force",
+			"--atomic",
 			"--set", "age=35",
 			"--set-string", "height=5ft10in",
 			"--values", "/usr/local/stats",