Add eslint config scratch

Author: DD Liu

.eslintignore

@@ -1,3 +1,4 @@
 node_modules/*
 dist/*
-playground/
+playground/
+webpack.config.js

.eslintrc.js

@@ -1,3 +1,3 @@
 module.exports = {
-    extends: ['scratch', 'scratch/node']
+    extends: ['scratch', 'scratch/es6', 'scratch/node']
 };

src/.eslintrc.js

@@ -0,0 +1,7 @@
+module.exports = {
+    root: true,
+    extends: ['scratch', 'scratch/es6', 'scratch/react'],
+    env: {
+        browser: true
+    }
+};

src/components/paper-canvas.jsx

@@ -10,10 +10,10 @@ class PaperCanvas extends React.Component {
     componentDidMount () {
         paper.setup('paper-canvas');
         // Create a Paper.js Path to draw a line into it:
-        var path = new paper.Path();
+        const path = new paper.Path();
         // Give the stroke a color
         path.strokeColor = 'black';
-        var start = new paper.Point(100, 100);
+        const start = new paper.Point(100, 100);
         // Move to start and draw a line from there
         path.moveTo(start);
         // Note that the plus operator on Point objects does not work