BREAKING CHANGE: `nyc` is no longer a peer dependency, instead
this module calls its API directly.

* use nyc as direct dependency

* feat: use nyc directly as a module

* skip binary install, close #163

* hide CircleCI PR env variables

* add typescript example

* run ts-example server

* update README file

* use command

* feat: move istanbul-lib-coverage from peer to prod dependencies

* describe how to generate other reports

* add link to Docker example, close #164