Add eslintrc. Update gitignore.

.eslintrc.js

@@ -0,0 +1,29 @@
+module.exports = {
+	"parserOptions": {
+		"ecmaVersion": 2018
+	},
+	"env": {
+		"node": true,
+		"es6": true
+	},
+	"extends": "eslint:recommended",
+	"rules": {
+		"indent": [ "error", "tab" ],
+		"operator-linebreak": [ "error", "before" ],
+		"semi": [ "error", "always" ],
+		"comma-dangle": [ "error", "only-multiline" ],
+		"quotes": [ "error", "double" ],
+		"no-tabs": [ "error", { "allowIndentationTabs": true } ],
+		"padded-blocks": 2,
+		"space-before-blocks": 2,
+		"comma-style": 2,
+		"no-console": 0,
+		"valid-typeof": 0,
+		"arrow-parens": 0,
+		"generator-star-spacing": 0,
+		"space-before-function-paren": 0,
+		"object-property-newline": 0,
+		"new-cap": 0,
+		"no-eval": 0
+	}
+};

.gitignore

@@ -1 +1 @@
-api_key.php
+node_modules