add version

Cargo.lock

@@ -578,7 +578,7 @@ dependencies = [
 
 [[package]]
 name = "rmdupe"
-version = "1.2.1"
+version = "2.0.1"
 dependencies = [
  "chrono",
  "futures",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rmdupe"
-version = "2.0.0"
+version = "2.0.1"
 authors = ["Avril <flanchan@cumallover.me>"]
 edition = "2018"
 

src/arg.rs

@@ -19,6 +19,9 @@ pub fn program() -> &'static str
 
 pub fn usage() -> !
 {
+    println!("rmdupe version {}", env!("CARGO_PKG_VERSION"));
+    println!(" by {}", env!("CARGO_PKG_AUTHORS"));
+    println!(" (licensed with GNU GPL v3)\n");
     println!("Usage: {} [OPTIONS] [--] <dirs...>", program());
     println!("Usage: {} --rebase [<files>]", program());
     println!("Usage: {} --help", program());