Add eslint for linting javascript files

.eslintrc

@@ -0,0 +1,42 @@
+{
+  "root": true,
+  "extends": "airbnb-base",
+  "env": {
+    "node": true,
+    "es6": true,
+    "mocha": true
+  },
+  "parserOptions": {
+    "ecmaVersion": 6,
+    "sourceType": "module",
+    "ecmaFeatures": {
+      "jsx": true,
+      "modules": true,
+      "experimentalObjectRestSpread": true
+    }
+  },
+  "rules": {
+    "one-var": 0,
+    "one-var-declaration-per-line": 0,
+    "new-cap": 0,
+    "consistent-return": 0,
+    "no-param-reassign": 0,
+    "import/no-unresolved": 0,
+    "comma-dangle": 0,
+    "curly": ["error", "multi-line"],
+    "no-shadow": ["error", { "allow": ["req", "done", "res", "err"] }],
+    "valid-jsdoc": [1, {
+      "requireReturn": false,
+      "requireReturnType": false,
+      "requireParamDescription": false,
+      "requireReturnDescription": false
+    }],
+    "require-jsdoc": [1, {
+        "require": {
+            "FunctionDeclaration": true,
+            "MethodDefinition": true,
+            "ClassDeclaration": true
+        }
+    }]
+  }
+}