Vendor dependencies

Let's see how I like this workflow.

vendor/fuchsia-cprng/Cargo.toml

@@ -0,0 +1,22 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g. crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+edition = "2018"
+name = "fuchsia-cprng"
+version = "0.1.1"
+authors = ["Erick Tryzelaar <etryzelaar@google.com>"]
+include = ["src/*.rs", "Cargo.toml", "AUTHORS", "LICENSE", "PATENTS"]
+description = "Rust crate for the Fuchsia cryptographically secure pseudorandom number generator"
+readme = "README.md"
+license-file = "LICENSE"
+repository = "https://fuchsia.googlesource.com/fuchsia/+/master/garnet/public/rust/fuchsia-cprng"