Rename serde_tests to testing

testing/build.rs

@@ -0,0 +1,17 @@
+extern crate serde_codegen;
+
+use std::env;
+use std::path::Path;
+
+fn main() {
+    let out_dir = env::var_os("OUT_DIR").unwrap();
+
+    for &(src, dst) in &[
+        ("tests/test.rs.in", "test.rs"),
+        ("benches/bench.rs.in", "bench.rs"),
+    ] {
+        let src = Path::new(src);
+        let dst = Path::new(&out_dir).join(dst);
+        serde_codegen::expand(&src, &dst).unwrap();
+    }
+}