Update minor version due to breaking API change

Thanks for the hint, @jbg.

Author: UjOwtuc

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "tokio-postgres-rustls"
 description = "Rustls integration for tokio-postgres"
-version = "0.8.1"
+version = "0.9.0"
 authors = ["Jasper Hugo <[email protected]>"]
 repository = "https://github.com/jbg/tokio-postgres-rustls"
 edition = "2018"