chore(package): update standard-version to version 7.1.0

Closes #13

Author: greenkeeper[bot]

package.json

@@ -8,7 +8,7 @@
   },
   "devDependencies": {
     "standard": "^11.0.0",
-    "standard-version": "^5.0.0",
+    "standard-version": "^7.1.0",
     "tap": "^14.2.3",
     "weallbehave": "^1.2.0",
     "weallcontribute": "^1.0.8"