Add Rust and Cargo nightlies

cargo-nightly.rb

@@ -0,0 +1,16 @@
+require 'formula'
+
+class CargoNightly < Formula
+  homepage 'http://crates.io/'
+  head 'http://static.rust-lang.org/cargo-dist/cargo-nightly-x86_64-apple-darwin.tar.gz'
+
+  # depends_on 'rust-nightly'
+
+  def install
+    system "./install.sh", "--prefix=#{prefix}"
+  end
+
+  test do
+    system "#{bin}/cargo"
+  end
+end

rust-nightly.rb

@@ -0,0 +1,17 @@
+require 'formula'
+
+class RustNightly < Formula
+  homepage 'http://www.rust-lang.org/'
+  head 'http://static.rust-lang.org/dist/rust-nightly-x86_64-apple-darwin.tar.gz'
+
+  conflicts_with 'rust', :because => 'same'
+
+  def install
+    system "./install.sh", "--prefix=#{prefix}"
+  end
+
+  test do
+    system "#{bin}/rustc"
+    system "#{bin}/rustdoc", "-h"
+  end
+end