cargo-download: init at 0.1.1

Cargo.nix was generated from cargo-download 0.1.1 with this patch
applied, which was necessary to not confuse carnix about the version
being different between Cargo.toml and Cargo.lock.

See https://github.com/Xion/cargo-download/pull/3.

From 5efd4cf11ff9d5042712303404169016b1e05c33 Mon Sep 17 00:00:00 2001
From: Alyssa Ross <hi@alyssa.is>
Date: Thu, 26 Jul 2018 21:19:06 +0200
Subject: [PATCH] Fix Cargo.lock

Running `cargo build` on a clean checkout produces a diff in Cargo.lock,
because it wasn't updated after the version number was bumped.

After this commit, `cargo build` should no longer produce a modified
working tree.
---
 Cargo.lock | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index cc7357c..c384dc1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -76,7 +76,7 @@ dependencies = [

 [[package]]
 name = "cargo-download"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
  "ansi_term 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.27.1 (registry+https://github.com/rust-lang/crates.io-index)",
--
2.17.1

pkgs/tools/package-management/cargo-download/default.nix

@@ -0,0 +1,5 @@
+{ lib, buildPlatform, buildRustCrate, fetchgit }:
+
+((import ./Cargo.nix { inherit lib buildPlatform buildRustCrate fetchgit; }).cargo_download {}).override {
+
+}

pkgs/top-level/all-packages.nix

@@ -7099,6 +7099,7 @@ with pkgs;
       };
     });
 
+  cargo-download = callPackage ../tools/package-management/cargo-download { };
   cargo-edit = callPackage ../tools/package-management/cargo-edit { };
   cargo-release = callPackage ../tools/package-management/cargo-release { };
   cargo-tree = callPackage ../tools/package-management/cargo-tree { };