message: Update async-trait crate to 0.1.48
diff: @@ -13,7 +13,7 @@ edition = "2018"
  [dependencies]
  # Temporary until https://github.com/rust-lang/rfcs/issues/2739, for
  # `maybe_async`.
  -async-trait = { version = "0.1.40", optional = true }
  +async-trait = { version = "0.1.48", optional = true }
  base64 = "0.13.0"
  chrono = { version = "0.4.13", features = ["serde", "rustc-serialize"] }
  derive_builder = "0.10.0"
  