Move rust sources into the repo's root (#76)

Currently, the core project is a cargo workspace with a single package
in the `rs/` directory containing the package's Cargo.toml and sources.
This prevents the crate from being published to crates.io, since the
`protos` dir is not part of the package directory.

To fix this, this change moves the contents of the `rs/` directory to
the root of repo, replacing the cargo worksapce with a single cargo
package.

Cargo.toml

@@ -1,4 +1,42 @@
-[workspace]
-members = [
-    "rs"
-]
+[package]
+name = "linkerd2-proxy-api"
+version = "0.2.0"
+authors = ["Linkerd Developers <cncf-linkerd-dev@lists.cncf.io>"]
+license = "Apache-2.0"
+edition = "2018"
+
+[features]
+default = []
+
+# Generate code that is compatible with Tonic's `transport` module.
+transport = ["tonic-build/transport", "tonic/transport"]
+
+# Generate code that is formatted.
+rustfmt = ["tonic-build/rustfmt"]
+
+# Enable generation of arbitrary protos with quickcheck.
+arbitrary = ["quickcheck"]
+
+# Determines whether clients or servers are built
+client = ["transport"]
+server = ["transport"]
+
+destination = ["http_types", "net", "prost-types"]
+http_types = ["http", "thiserror"]
+identity = ["prost-types"]
+inbound = ["net", "prost-types"]
+net = ["ipnet", "thiserror"]
+tap = ["h2", "http_types", "net", "prost-types"]
+
+[dependencies]
+h2 = { version = "0.3", optional = true }
+http = { version = "0.2", optional = true }
+ipnet = { version = "2", optional = true }
+prost = "0.8"
+prost-types = { version = "0.8", optional = true }
+quickcheck = { version = "1", default-features = false, optional = true }
+thiserror = { version = "1", optional = true }
+tonic = { version = "0.5", default-features = false, features = ["prost", "codegen"] }
+
+[build-dependencies]
+tonic-build = { version = "0.5", default-features = false, features = ["prost"] }

Makefile

@@ -41,7 +41,7 @@ $(PROTOC):
 	rm $(PROTOC).zip
 	chmod 755 $(PROTOC)
 
-Cargo.lock: Cargo.toml rs/Cargo.toml
+Cargo.lock: Cargo.toml
 	$(CARGO) fetch
 
 .PHONY: rs

rs/build.rs → build.rs

@@ -1,6 +1,6 @@
 use std::error::Error;
 
-const DIR: &str = "../proto";
+const DIR: &str = "proto";
 const PROTOS: [&str; 6] = [
     "destination",
     "http_types",