(#84) storage: storing `undefined` now causes the entry to be removed
Merge branch 'feature-0.16.x/84-storage-fix-storing-of-undefined' into release-0.16.x

* feature-0.16.x/84-storage-fix-storing-of-undefined:
  (#84) storage: storing `undefined` now causes the entry to be removed
release v0.16.1