Add a few tests and compilation on MacOS (and other non-Linux Unixes).

[alexeyklyukin]

This is a PR against the import branch.

• add necessary includes for basename on non-Linux systems.
• use python3 to generate parquet files
• add a float8 column and attribute that are null
• set log_statement to 'none' in the tests.

[zilder]

Hi @alexeyklyukin,

looks good, thanks a lot!