update deps and upgrade self to v0.6.4

Author: rainliu

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rtcp"
-version = "0.6.3"
+version = "0.6.4"
 authors = ["Rain Liu <[email protected]>", "Michael Uti <[email protected]>"]
 edition = "2018"
 description = "A pure Rust implementation of RTCP"
@@ -10,10 +10,10 @@ homepage = "https://webrtc.rs"
 repository = "https://github.com/webrtc-rs/rtcp"
 
 [dependencies]
-util = { package = "webrtc-util", version = "0.5.2", default-features = false, features = ["marshal"] }
+util = { package = "webrtc-util", version = "0.5.3", default-features = false, features = ["marshal"] }
 bytes = "1.1.0"
 thiserror = "1.0.30"
 
 [dev-dependencies]
-tokio = { version = "1.13.0", features = ["sync"] }
+tokio = { version = "1.15.0", features = ["sync"] }
 tokio-test = "0.4.2"