Add dev dependencies and cleanup ESLint file (#588)

.eslintrc.json

@@ -0,0 +1,20 @@
+{
+  "extends": "airbnb",
+  "plugins": [
+    "import",
+    "react",
+    "jsx-a11y"
+  ],
+  "rules": {
+    "max-len": [2, 120, 2],
+    "no-underscore-dangle": 0,
+    "global-require": 0,
+    "guard-for-in": 0,
+    "no-restricted-syntax": 0,
+    "no-param-reassign": 0,
+    "consistent-return": 0,
+    "import/no-extraneous-dependencies": 0,
+    "no-continue": 0,
+    "no-confusing-arrow" : 0
+  }
+}