Pq-sys 0.6.0

Changed

• The bundled feature of pq-sys no longer build a bundled version of openssl.
  To bundle openssl when compiling libpq from source, add openssl-sys with the vendored feature to your crate dependencies:

  [dependencies]
  openssl-sys = { version = "0.9.93", features = ["vendored"] }

Full Changelog: v0.5.0...v0.6.0