Bigtableql

Fix

- support sparse cells across qualifiers

**Full Changelog**: https://github.com/jychen7/BigtableQL/compare/v0.1.8...v0.1.9

Fix

- support group by timestamp

**Full Changelog**: https://github.com/jychen7/BigtableQL/compare/v0.1.7...v0.1.8

Fix
- fix exception when scan result contains 0 rows

**Full Changelog**: https://github.com/jychen7/BigtableQL/compare/v0.1.6...v0.1.7

New

- supports predicate pushdown (Bigtable ValueRangeFilter)

**Full Changelog**: https://github.com/jychen7/BigtableQL/compare/v0.1.5...v0.1.6

New
support
- Alias
- Cast
- Math functions

**Full Changelog**: https://github.com/jychen7/BigtableQL/compare/v0.1.4...v0.1.5

New
* downgrade numpy to support py 3.7 by jychen7 in https://github.com/jychen7/BigtableQL/pull/1

**Full Changelog**: https://github.com/jychen7/BigtableQL/compare/v0.1.3...v0.1.4