- All requests method changed to POST (in order to prevent the scanners
from messing with the _method attribute, which leads to invalid
requests).
- Finder option uniq input changed to checkbox (to provide the scanners
with some extra guidance).
- Timestamp column removed from attribute fields used in create or
  update (leads to false positives about misformat of timestamp).
- Made the _attributes partial shared and use them for create, read and
  update tests.