[CALCITE-2728] Update appveyor.yml to enable appveyor testing against JDK 11
[CALCITE-2728] Update appveyor.yml to enable appveyor testing against JDK 11

Close apache/calcite-avatica#81

apache/calcite-avatica,apache/calcite-avatica,looker-open-source/calcite-avatica,apache/calcite-avatica,looker-open-source/calcite-avatica,apache/calcite-avatica,looker-open-source/calcite-avatica,looker-open-source/calcite-avatica,apache/calcite-avatica,looker-open-source/calcite-avatica