test: nyc upgrade to v15

Author: lamweili

test/sandbox-coverage.js

@@ -5,12 +5,14 @@ const NYC = require('nyc');
 
 sandbox.configure({
   sourceTransformers: {
-    nyc: function (source) {
+    nyc(source) {
       if (this.filename.indexOf('node_modules') > -1) {
         return source;
       }
-      const nyc = new NYC();
-      return nyc.instrumenter().instrumentSync(source, this.filename);
-    }
-  }
+      const nyc = new NYC({});
+      return nyc
+        .instrumenter()
+        .instrumentSync(source, this.filename, { registerMap: () => {} });
+    },
+  },
 });