incrimental changes
added Snapshot States of SKIPPED and ERROR to cover GCE needs.
folder support
fixed tests
Merge pull request #265 from unwin/develop

Develop
added child folder attribute so we can navigate both directions
Merge remote-tracking branch 'upstream/develop' into develop
Merge pull request #266 from daniellemayne/develop

Develop
Minor improvements, mostly style and deprecations
Initial changes to core to support backups in addition to snapshots in
RDS.
Merge pull request #268 from maksimov/develop

Minor improvements, mostly style and deprecations
Merge pull request #272 from unwin/develop

Initial changes to core to support backups in addition to snapshots in
Merge branch 'develop' of https://github.com/greese/dasein-cloud-core into develop