fix(package): update execa to version 1.0.0

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "babel-preset-env": "^1.6.1",
     "babel-register": "^6.26.0",
     "chalk": "^2.1.0",
-    "execa": "^0.11.0",
+    "execa": "^1.0.0",
     "got": "^9.1.0",
     "p-retry": "^2.0.0",
     "semver": "^5.4.1",