fix(package): update execa to version 0.11.0

Author: greenkeeper[bot]

package.json

@@ -20,7 +20,7 @@
     "aggregate-error": "^1.0.0",
     "debug": "^3.1.0",
     "dir-glob": "^2.0.0",
-    "execa": "^0.10.0",
+    "execa": "^0.11.0",
     "fs-extra": "^7.0.0",
     "globby": "^8.0.1",
     "lodash": "^4.17.4",