Resolve issue with Cucumber-js v1.2.1

xolvio/chimp#441
cucumber/cucumber-js#610

The latest version of Chimp uses Cucumber-js v1.2.1 which appears to have an issue when any unexpected error is thrown (e.g. element not found).

It looks like cucumber-js have fixed this, but until Chimp updates to the lastest version am downgrading Chimp to a version that uses Cucumber-js v1.2.0

package.json

@@ -7,7 +7,7 @@
     "node": "4.4.7"
   },
   "dependencies": {
-    "chimp": "^0.39.3"
+    "chimp": "0.38.0"
   },
   "scripts": {
     "test": "node node_modules/chimp/dist/bin/chimp.js"