upgrade eslint to fix babel/babel-eslint#243

babel-eslint -> devDep

revert dep prop deletion

Author: emflores

package.json

@@ -30,7 +30,7 @@
   "devDependencies": {
     "babel": "6.3.26",
     "babel-core": "6.4.5",
-    "babel-eslint": "5.0.0-beta6",
+    "babel-eslint": "^6.1.2",
     "babel-loader": "6.2.1",
     "babel-plugin-add-module-exports": "0.1.2",
     "babel-preset-es2015": "6.3.13",