Merge pull request #101 from mozilla/greenkeeper-eslint-1.7.0

Update eslint to version 1.7.0 🚀

package.json

@@ -48,7 +48,7 @@
     "columnify": "1.5.2",
     "css": "2.2.1",
     "es6-promisify": "3.0.0",
-    "eslint": "1.6.0",
+    "eslint": "1.7.0",
     "semver": "5.0.3",
     "xmldom": "0.1.19",
     "yargs": "3.27.0",