show correct version in -v

src/lib.rs

@@ -12,3 +12,5 @@ pub mod history;
 pub mod menu;
 pub mod text;
 pub mod ui;
+
+pub const VERSION: &'static str = env!("CARGO_PKG_VERSION");

src/main.rs

@@ -48,7 +48,7 @@ fn main() {
 }
 
 fn print_version() {
-    println!("phetch v0.0.1-dev");
+    println!("phetch v{}", phetch::VERSION);
 }
 
 fn print_usage() {