Configure eslint

- run from `app` using `npx eslint .`

app/.eslintignore

@@ -0,0 +1,6 @@
+node_modules/
+build
+test/fixtures
+test/tests
+razzle.config.js
+packages/create-razzle-app/templates

app/.eslintrc

@@ -0,0 +1,33 @@
+{
+  "extends": [
+    "eslint:recommended",
+    "plugin:react/recommended"
+  ],
+  "env": {
+    "browser": true,
+    "commonjs": true,
+    "node": true,
+    "es6": true
+  },
+  "parser": "babel-eslint",
+  "parserOptions": {
+    "ecmaVersion": 6,
+    "sourceType": "module",
+    "ecmaFeatures": {
+      "jsx": true
+    }
+  },
+  "rules": {
+    "no-console": "off",
+    "strict": ["error", "global"],
+    "curly": "warn"
+  },
+  "plugins": [
+    "react"
+  ],
+  "settings": {
+    "react": {
+      "version": "detect"
+    }
+  }
+}