change object initialization so there is less need to manage context. rename del to delFeature for clarity
update if feature.id is set. fixes #45
update cover opts and cli
update test
return feature collections everywhere. closes #49
return empty feature collections, err if update and feature doesnt exist
add test for index item count after update, update to dyno 0.4.6 for batch item fix, ref: https://github.com/mapbox/dyno/pull/16
Merge pull request #45 from mapbox/update

update feature