Fix CrateDB setup used for testing, adds jdk 11
Fix CrateDB setup used for testing, adds jdk 11

Since CrateDB >= 4.0 java versions >= 11 are required.
Also switched installing CrateDB from install.crate.io to
use the latest version of the `stable` ubuntu channel.

crate/crate-pdo,crate/crate-pdo