Vendor dependencies

Let's see how I like this workflow.

vendor/users/examples/example.rs

@@ -0,0 +1,20 @@
+extern crate users;
+use users::{Users, Groups, UsersCache};
+
+extern crate env_logger;
+
+
+fn main() {
+    env_logger::init();
+
+	let cache = UsersCache::new();
+
+	let current_uid = cache.get_current_uid();
+	println!("Your UID is {}", current_uid);
+
+	let you = cache.get_user_by_uid(current_uid).expect("No entry for current user!");
+	println!("Your username is {}", you.name().to_string_lossy());
+
+	let primary_group = cache.get_group_by_gid(you.primary_group_id()).expect("No entry for your primary group!");
+	println!("Your primary group has ID {} and name {}", primary_group.gid(), primary_group.name().to_string_lossy());
+}