Gzip does not exist as a flag, use zlib
Merge pull request #31 from infosiftr/fix-gzip

Gzip does not exist as a flag, use zlib
Remove buildconf from our Dockerfiles since we use the release tarballs, which have pre-generated configure scripts
Merge pull request #32 from infosiftr/remove-buildconf

Remove buildconf from our Dockerfiles since we use the release tarballs...