Merge pull request #350 from erickt/develop

Bump version
diff --git a/tuf/Cargo.toml b/tuf/Cargo.toml
index 5e0c500..60539b4 100644
--- a/tuf/Cargo.toml
+++ b/tuf/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "tuf"
 edition = "2018"
-version = "0.3.0-beta3"
+version = "0.3.0-beta4"
 authors = [ "heartsucker <heartsucker@autistici.org>", "Erick Tryzelaar <etryzelaar@google.com>" ]
 description = "Library for The Update Framework (TUF)"
 homepage = "https://github.com/heartsucker/rust-tuf"