Fix version to 0.4.0.
[package]
name = "routinator"
-version = "0.3.4"
+version = "0.4.0"
authors = ["The NLnet Labs RPKI Team <rpki@nlnetlabs.nl>"]
description = "An RPKI relying party software."
repository = "https://github.com/NLnetLabs/routinator"
