add tests for stutter lints

tests/compile-fail/stutter.rs

@@ -0,0 +1,14 @@
+#![feature(plugin)]
+#![plugin(clippy)]
+#![deny(stutter)]
+#![allow(dead_code)]
+
+mod foo {
+    pub fn foo() {}
+    pub fn foo_bar() {} //~ ERROR: item name starts with its containing module's name
+    pub fn bar_foo() {} //~ ERROR: item name ends with its containing module's name
+    pub struct FooCake {} //~ ERROR: item name starts with its containing module's name
+    pub enum CakeFoo {} //~ ERROR: item name ends with its containing module's name
+}
+
+fn main() {}