added docs for installing vagrant dev environment

I needed to run these commands to get things to work in the local environment

I have not verified that the `ssh-copy-id` is still needed.

Are there other steps I should be running?

Thanks
I'm not sure this is the line we want here. Pinging @hamiltont but I think the following is more appropriate:
```bash
toolset/run-tests.py --install-only --install server
toolset/run-tests.py --install-only --install database
toolset/run-tests.py --install-only --install client
```
This may end up being the same thing, but I'm not positive. Also, having the `--test` flag is superfluous (or should be) for `--install`