Don't exit vagrant installation until api-server is available

[aaronlevy]

In the vagrant examples, the machines will be up, but all of the assets on the host may not have started running yet. This often leads to confusion where users think something is broken (but it is still downloading / starting assets).

An option here would be to block exit until the api-server is available, and add stdout info that it is waiting.

[MattFriedman]

+1 If possible please also include some console output to indicate what is happening. Many thanks.

[grebois]

+1