Bump Netlify open-api version

[keiko713]

We made several changes since we bumped the version last, so let's bump it.
Also use vX.Y.Z format.

[keiko713]

Ok sadly this is 🐇 🕳 .
The SiteSetup model shape in netlifyctl is like this (https://github.com/netlify/netlifyctl/blob/master/commands/init/init.go#L98-L101):

		setup := &models.SiteSetup{
			Site: *site,
			Repo: info,
		}

However, in open-api, we have changed this into somewhat different shape in netlify/open-api@a2fcf18#diff-7e7ec16647c95450034b610f374a5f10

This doesn't work. We need to think either 1) changing open-api (maybe to non flatten mode) or 2) changing netlifyctl to match with the current open-api.
Since there is no rush for releasing new version. I'll... just leave it for now.

[bcomnes]

I don't quote have enough context to know whats right, so I'll take your word for it when you decide.

[bcomnes]

Just to get a review in here: Approved when tests pass