v1.0.0 - breaking stuff to look tough

1. d37c8f2 added a context to Transport.Token, this was exported, but unlikely to be used by most use cases. See #21
2. 344ce85 changed the AppID type from int to int64 to follow go-github's convention. See #27.

See #32

Thanks to all contributors @wlynch @emoryruscus @roboll @ricardochimal @kamontia @aidansteele @Philmod and the https://github.com/google/go-github team!