--update: env for eslint and jest

Author: ashokdey

Diff for: .eslintrc.json

@@ -1,3 +1,7 @@
 {
-    "extends": "airbnb-base"
-}
+  "env": {
+    "node": true,
+    "jest": true
+  },
+  "extends": "airbnb-base"
+}

Diff for: package.json

@@ -7,6 +7,9 @@
     "test": "jest --verbose",
     "test:watch": "jest --watchAll"
   },
+  "jest": {
+    "testEnvironment": "node"
+  },
   "keywords": [],
   "author": "Ashok Dey <ashokdey100@gmail.com> (http://ashokdey.in)",
   "license": "MIT",