fix test for wasm-bindgen 0.2.21

tests/all/build.rs

@@ -242,7 +242,7 @@ fn it_format_out_dir_on_windows() {
 
     let wasm_pack_log = utils::file::read_file(&fixture.path.join("wasm-pack.log")).unwrap();
     assert!(
-        wasm_pack_log.contains(r"Your wasm pkg is ready to publish at c:\Users\"),
+        wasm_pack_log.contains(r"Your wasm pkg is ready to publish at C:\Users\"),
         "directories in wasm-pack.log should be well formatted",
     );
 }