Use public CircleCI context for build secrets (#85)
Use public CircleCI context for build secrets (#85)

* we created a new public context that's identical to the old context,
with the exception of Github token, which is scoped to public repos only
* Github token in the other context is scoped to public and private repos
* (both contexts are still internal to Honeycomb)
* this reduces the security exposure of builds
honeycombio/libhoney-js