Merge pull request #49 from jokeyrhyme/greenkeeper/execa-0.8.0

Update execa to the latest version 🚀

Author: jokeyrhyme

package.json

@@ -17,7 +17,7 @@
     "eslint-plugin-node": "^4.2.2",
     "eslint-plugin-promise": "^3.5.0",
     "eslint-plugin-standard": "^3.0.1",
-    "execa": "^0.7.0",
+    "execa": "^0.8.0",
     "fixpack": "^2.3.1",
     "nyc": "^11.0.1"
   },