Log Message:
blosc: updated to 1.18.1

Changes from 1.17.1 to 1.18.1
- Fixed the copy of the leftovers of a chunk when its size is not a
  multiple of the typesize.  Although this is a very unusual situation,
  it can certainly happen (e.g.
  https://github.com/Blosc/python-blosc/issues/220).