fix(deps): update dependency execa to v1 (#24)

Author: renovate[bot]

package.json

@@ -95,7 +95,7 @@
     "bluebird": "3.5.1",
     "check-more-types": "2.24.0",
     "debug": "3.1.0",
-    "execa": "0.11.0",
+    "execa": "1.0.0",
     "lazy-ass": "1.6.0"
   }
 }