[bazel] Fix the Rust build and bump rules_rust

The Rust source in the project contains both a `lib.rs` and
a `main.rs`. Cargo is smart enough to understand that this
means it needs to compile a library and then a binary, but
Bazel needs to be told this explicitly.

Author: shs96c

WORKSPACE

@@ -160,10 +160,8 @@ selenium_register_dotnet()
 
 http_archive(
     name = "rules_rust",
-    sha256 = "dd79bd4e2e2adabae738c5e93c36d351cf18071ff2acf6590190acf4138984f6",
-    urls = [
-        "https://github.com/bazelbuild/rules_rust/releases/download/0.14.0/rules_rust-v0.14.0.tar.gz",
-    ],
+    sha256 = "5c2b6745236f8ce547f82eeacbbcc81d736734cc8bd92e60d3e3cdfa6e167bb5",
+    urls = ["https://github.com/bazelbuild/rules_rust/releases/download/0.15.0/rules_rust-v0.15.0.tar.gz"],
 )
 
 load("@rules_rust//rust:repositories.bzl", "rules_rust_dependencies", "rust_register_toolchains")
@@ -237,11 +235,11 @@ http_archive(
     patches = [
         "//py:rules_pkg_tree.patch",
     ],
+    sha256 = "eea0f59c28a9241156a47d7a8e32db9122f3d50b505fae0f33de6ce4d9b61834",
     urls = [
         "https://mirror.bazel.build/github.com/bazelbuild/rules_pkg/releases/download/0.8.0/rules_pkg-0.8.0.tar.gz",
         "https://github.com/bazelbuild/rules_pkg/releases/download/0.8.0/rules_pkg-0.8.0.tar.gz",
     ],
-    sha256 = "eea0f59c28a9241156a47d7a8e32db9122f3d50b505fae0f33de6ce4d9b61834",
 )
 
 load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")

rust/BUILD.bazel

@@ -1,9 +1,25 @@
 load("@crates//:defs.bzl", "all_crate_deps")
-load("@rules_rust//rust:defs.bzl", "rust_binary")
+load("@rules_rust//rust:defs.bzl", "rust_binary", "rust_library")
 
 rust_binary(
+    # Yes, this name is very similar to the library. Note the dash
+    # instead of an underscore
     name = "selenium-manager",
-    srcs = glob(["src/**/*.rs"]),
-    edition = "2018",
+    srcs = ["src/main.rs"],
+    edition = "2021",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":selenium_manager",
+    ] + all_crate_deps(normal = True),
+)
+
+rust_library(
+    # The name here is used as the crate name
+    name = "selenium_manager",
+    srcs = glob(
+        ["src/**/*.rs"],
+        exclude = ["main.rs"],
+    ),
+    edition = "2021",
     deps = all_crate_deps(normal = True),
 )