disable tap-diff for now, it is exiting with an error code prematurely

Author: Rich-Harris

package.json

@@ -9,7 +9,7 @@
     "build": "rollup -c",
     "dev": "rollup -cw",
     "prepublishOnly": "npm test",
-    "test": "node test/runner.js | tap-diff",
+    "test": "node test/runner.js",
     "test:browser": "npm run build && serve test/public",
     "pretest": "npm run build"
   },