Very rough code that can helm install

The recommended way to test code that uses exec.Cmd involves setting up
a real exec.Cmd that invokes `go test` with additional arguments that
fire off a specially-constructed test that behaves the way the mocked-
out script would be expected to do. It's a sensible way to test exec.Cmd
itself, but for code that merely invokes it, I think it makes more sense
to use actual mocks.

internal/run/install.go

@@ -0,0 +1,19 @@
+package run
+
+import ()
+
+const HELM_BIN = "/usr/bin/helm"
+
+func Install(args ...string) error {
+	cmd := &execCmd{}
+	cmd.Path(HELM_BIN)
+
+	return install(cmd, args)
+}
+
+func install(cmd cmd, args []string) error {
+	args = append([]string{"install"}, args...)
+	cmd.Args(args)
+
+	return cmd.Run()
+}