Add droplet create command

[AGMETEOR]

/do droplet <name>
Only sysadmins or some other authorized party should run this command.

Create a UI element with dropdown options for Name, Size, Region and the Image used to create the droplet.
The region, size comes fromregions, resp, err := client.Regions.List(context.TODO(), opts)
Each region comes with an array of sizes it supports.
Image info from from images, resp, err := client.Images.List(context.TODO(), opts)