Include parquet_s3_fdw

[ibotty]

It would be great to use https://github.com/pgspider/parquet_s3_fdw.

Would you accept a pull request that builds the extension when building spilo? Unfortunately I won't have time in the near future to package it and get it into apt.postgresql.org (pgspider/parquet_s3_fdw#15), I might find time to update spilo to build it locally though.

[hughcapet]

I am afraid, no. We are not planning to include more extensions that are not available as packages and need to be built from source.