Setup missing badges

[![AppVeyor build status](https://ci.appveyor.com/api/projects/status/github/canjs/can-model?branch=master&svg=true)](https://ci.appveyor.com/project/matthewp/can-model)
[![Coverage status](https://coveralls.io/repos/github/canjs/can-model/badge.svg?branch=master)](https://coveralls.io/github/canjs/can-model?branch=master)