Improve coverage on tests with babel

TypeScript compiled to ES6 doesn't change much, so we now test ES6 code
so that coverage report is a bit more accurate. Added 'babel-jest',
'babel-preset-es2015' and 'babel-preset-react' as dev dependencies as
well as a '.babelrc' file so that jest can transpile the ES6 code and
report coverage.
Added Enzyme as dev dependency to use the shallow renderer so that we can
actually test that Link is being used.

Updated readme with install instructions

.babelrc

@@ -0,0 +1,3 @@
+{
+  "presets": ["es2015", "react"]
+}

.npmignore

@@ -4,3 +4,5 @@ coverage
 *.js.map
 *.test.js
 *.log
+.babelrc
+src/__snapshots__/

README.md

@@ -4,8 +4,16 @@
 
 Easily integrate [React Router](https://reacttraining.com/react-router/) with [simple-commonmark-react](https://github.com/GAumala/simple-commonmark-react)
 
+## Install
+
+```
+yarn add simple-commonmark-react-router
+```
+
 ## Example
 
+The following example renders markdown links with React Router's Link component.
+
 ```javascript
 import React from 'react'
 import {

package.json

@@ -13,19 +13,24 @@
   "devDependencies": {
     "@types/commonmark": "^0.22.29",
     "@types/react": "^15.0.25",
+    "babel-jest": "^20.0.3",
+    "babel-preset-es2015": "^6.24.1",
+    "babel-preset-react": "^6.24.1",
     "coveralls": "^2.13.1",
+    "enzyme": "^2.8.2",
     "jest": "^20.0.4",
     "react": "^15.5.4",
     "react-dom": "^15.5.4",
     "react-router-dom": "^4.1.1",
+    "react-test-renderer": "^15.5.4",
     "simple-commonmark-react": "^0.5.0",
     "typescript": "^2.3.4"
   },
   "scripts": {
     "test": "jest --coverage",
     "build": "tsc -d ./src/ReactRouterLinkRenderer.ts",
     "dev": "yarn run build && yarn test",
-    "ci": "yarn run build && yarn test && cat ./coverage/lcov.info | coveralls",
+    "ci": "yarn run build -- --target es2015 --moduleResolution node && yarn test && cat ./coverage/lcov.info | coveralls",
     "release": "yarn run tsc && publish"
   }
 }

src/ReactRouterLinkRenderer.test.js

@@ -1,17 +1,23 @@
-const ReactRouterLinkRenderer = require('./ReactRouterLinkRenderer.js').default
-const renderNodes = require('simple-commonmark-react').renderNodes
+import React from 'react';
+import renderer from 'react-test-renderer';
+import { BrowserRouter as Router, Link } from 'react-router-dom'
+import { shallow } from 'enzyme';
 
-test('should render links with React Router\'s Link', () => {
-  const options = { customRenderers: { link: ReactRouterLinkRenderer } }
-  const markdown = 'Here is a [link](/some/path)'
+import  ReactRouterLinkRenderer from './ReactRouterLinkRenderer.js'
+import { renderNodes } from 'simple-commonmark-react'
 
-  const nodes = renderNodes(markdown, options)
-  expect(nodes.length).toEqual(1)
+const options = { customRenderers: { link: ReactRouterLinkRenderer } }
+const markdown = 'Here is a [link](/some/path)'
+const nodes = renderNodes(markdown, options)
 
-  const paragraph = nodes[0]
-  expect(paragraph.props.children.length).toEqual(2)
+test('should render markdown correctly', () => {
+  const component = renderer.create(<Router><div>{ nodes }</div></Router>)
+  const tree = component.toJSON()
+  expect(tree).toMatchSnapshot()
+})
 
-  const link = paragraph.props.children[1]
-  expect(link.props.to).toEqual('/some/path')
-  expect(link.props.children).toEqual(['link'])
+test('should render markdown with React Router\'s Link', () => {
+	const paragraphWrapper = shallow(nodes[0])
+  expect(paragraphWrapper.find(Link).length).toEqual(1)
 })
+

src/__snapshots__/ReactRouterLinkRenderer.test.js.snap

@@ -0,0 +1,18 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`should render markdown correctly 1`] = `
+<div>
+  <p
+    className={undefined}
+  >
+    Here is a 
+    <a
+      className={undefined}
+      href="/some/path"
+      onClick={[Function]}
+    >
+      link
+    </a>
+  </p>
+</div>
+`;