Merge pull request #7 from yosuke-furukawa/renovate/mocha-7.x

Update dependency mocha to v7

package.json

@@ -30,6 +30,6 @@
     "simple-bufferstream": "0.0.4"
   },
   "devDependencies": {
-    "mocha": "2.5.3"
+    "mocha": "7.1.2"
   }
 }