Revert "Merge pull request #1104 from isao/descriptors"

This reverts commit 602440d779f2e050c4c6306b50ffaaf9ce2e85f0, reversing
changes made to 37513ce7c2ef53318c1eb186ff673ad6fc525411.
ycb ~1.0.5
Merge pull request #1114 from isao/descriptors

revert arrow, descriptor upgrade commit