Update rubycommand

[godrei]

Checklist

• I've read and accepted the Contribution Guidelines

Context

This PR finishes the previous go-utils package update in the command/rubycommand package and in the command/gems/bundler.go file.

The previous migration introduced a global temporaryFactory, which blocks us in the generated command.Command customization (setting command.Opts for specifying work dir for example).

An example of how to adopt these changes: bitrise-steplib/steps-fastlane#84.

To finalize this PR a related go-utils PR needs to be merged and go-utils dependency needs to be updated here.

Changes

• Introduce ruby.CommandFactory interface and implementing commandFactory struct for creating ruby related commands.

  • CommandFactory.Create replaces the previous rubycommand.NewWithParams, rubycommand.NewFromSlice and rubycommand.New functions.
  • CreateBundleExec replaces the previous gems.BundleExecPrefix functionality.
  • CreateBundleInstall replaces the previous gems.BundleInstallCommand function.
  • CreateGemInstall replaces the previous rubycommand.GemInstall function.
  • CreateGemUpdate replaces the previous rubycommand.GemUpdate function.

• Introduce ruby.Environment interface and implementing environment struct.

  • RubyInstallType replaces the previous rubycommand.RubyInstallType function.
  • IsGemInstalled replaces the previous rubycommand. IsGemInstalled function.
  • IsSpecifiedRbenvRubyInstalled replaces the previous rubycommand. IsSpecifiedRbenvRubyInstalled function.

• gems.InstallBundlerCommand removed in favor of:

cmds := factory.CreateGemInstall("bunder", "1.0.0", false, true, &command.Opts{
	Stdout: os.Stdout,
	Stderr: os.Stderr,
	Dir:    workDir,
})
for _, cmd := range cmds {
	log.Donef("$ %s", cmd.PrintableCommandArgs())
	fmt.Println()

	if err := cmd.Run(); err != nil {
		failf("command failed, error: %s", err)
	}
}

• gems.RbenvVersionsCommand removed in favor of:

if _, err := cmdLocator.LookPath("rbenv"); err != nil {
	cmd := factory.Create("rbenv", []string{"versions"}, &command.Opts{
		Stderr: os.Stderr,
		Stdout: os.Stdout,
		Dir:    workDir,
	})

	fmt.Println()
	log.Donef("$ %s", cmd.PrintableCommandArgs())
	if err := cmd.Run(); err != nil {
		log.Warnf("%s", err)
	}
}

• create mocks for ruby.CommandFactory and ruby.Environment.

Investigation details

Decisions

[ofalvai]

nit: I would use a more descriptive arg name than slice, something like command