Requesting reviews for Avatica PRs

[Francis Chuang]

Hey all,

As rc0 for Avatica is going to be built once Kevin gets CALCITE-2972 in, 
can someone please review these PRs if they've got some spare cycles?

- https://github.com/apache/calcite-avatica/pull/89

- https://github.com/apache/calcite-avatica/pull/86

Vladimir, can you merge 
https://github.com/apache/calcite-avatica/pull/85 if it's ready?

Francis