Merge pull request #512 from janl/greenkeeper-eslint-1.7.3

Update eslint to version 1.7.3 🚀

package.json

@@ -41,7 +41,7 @@
   },
   "devDependencies": {
     "chai": "3.4.0",
-    "eslint": "1.7.2",
+    "eslint": "1.7.3",
     "mocha": "^2.1.0",
     "zuul": "^2.1.1"
   },