Upgrade parking-lot

Author: sfackler

tokio-postgres/Cargo.toml

@@ -40,7 +40,7 @@ bytes = "0.5"
 fallible-iterator = "0.2"
 futures = "0.3"
 log = "0.4"
-parking_lot = "0.9"
+parking_lot = "0.10"
 percent-encoding = "2.0"
 pin-project-lite = "0.1"
 phf = "0.8"