simpler yage test macro

no need to make a repetition with a pattern matching recurssion, it's already
available in the macro syntax

tests/common.rs

@@ -34,19 +34,11 @@ impl TestString for String {
 
 #[macro_export]
 macro_rules! yage {
-    () => (
-        Command::cargo_bin("yage").unwrap().assert()
-    );
-    ( $( $v:expr ),* ) => (
-        yage_args!(Command::cargo_bin("yage").unwrap(), $($v),*).assert()
-    );
-}
-
-#[macro_export]
-macro_rules! yage_args {
-    ($x:expr) => ($x);
-    ($x:expr, $y:expr) => ($x.arg($y));
-    ($x:expr, $y:expr, $($z:expr),+) => (
-        yage_args!($x.arg($y), $($z),*)
-    );
+    ( $( $v:expr ),* ) => ({
+        let mut cmd = Command::cargo_bin("yage").unwrap();
+        $(
+            cmd.arg($v);
+        )*
+        cmd.assert()
+    });
 }