Bump uuid version

Closes sfackler#231

Author: sfackler

postgres-shared/Cargo.toml

@@ -27,4 +27,4 @@ eui48 = { version = "0.1", optional = true }
 rustc-serialize = { version = "0.3", optional = true }
 serde_json = { version = ">= 0.6, < 0.10", optional = true }
 time = { version = "0.1.14", optional = true }
-uuid = { version = ">= 0.1, < 0.4", optional = true }
+uuid = { version = ">= 0.1, < 0.5", optional = true }