Merge pull request #21 from jo/greenkeeper-tap-spec-4.1.0

Update tap-spec to version 4.1.0 🚀

Author: jo

package.json

@@ -28,7 +28,7 @@
     "minimist": "1.2.0"
   },
   "devDependencies": {
-    "tap-spec": "3.0.0",
+    "tap-spec": "4.1.0",
     "tape": "4.2.1",
     "semantic-release": "6.0.3"
   }