0.9.0

Overview

The most important changes are the new crud.len() function and optimizations
in crud.select() / crud.pairs().

Added

• crud.len() function to calculate the number of tuples
  in the space for memtx engine and calculate the maximum
  approximate number of tuples in the space for vinyl engine.
• Testing: added integration with service coveralls.io (PR #195).
• Testing: added integration with luacov that allows to generate report with
  code coverage statistics (PR #195).

Changed

• Names of errors generated by CRUD operations have been unified (PR #184).
• Opmimize crud.select() / crud.pairs() for one replicaset case (say, when
  bucket_id is passed or deducible from conditions). It gives 13% boost on
  the case from #220 (PR #226).

Fixed

• Ignoring of an error in crud.pairs() (#144).
• Damaging of opts table by CRUD methods (#192).
• Ignoring of bucket_id option in crud.select()/crud.pairs() (#220).