Vagrant: Add `vagrant update` to update the CLI

[AllanOricil]

Other CLIs out there have a command to update from the terminal. It is usually CLI_NAME update. I think it would be good to us.

[soapy1]

Hey there, thanks for opening up an issue. I think the behavior you are looking for already exists within Vagrant. The vagrant reload command will reload the machine, applying any changes that may have been made in the Vagrantfile. You may also re-provision a machine using the vagrant provision command.

[AllanOricil]

Hi @soapy1. What Im looking for is a command to update the CLI to the latest version. I was using version 2.0.1 and to update to the latest version I had to download vagrant again from the website. BUt if I had a vagrant update command It would not be necessary.