Add babel build for npm package

Author: dfcook

.gitignore

@@ -1,6 +1,6 @@
 node_modules
 coverage
-dist
+npm
 .opt-in
 .opt-out
 .DS_Store

.npmignore

@@ -0,0 +1 @@
+/src/

package.json

@@ -2,16 +2,18 @@
   "name": "vue-testing-library",
   "version": "0.1.10",
   "description": "Simple and complete Vue DOM testing utilities that encourage good testing practices.",
-  "main": "src/index.js",
+  "main": "npm/index.js",
   "scripts": {
     "test": "jest --coverage",
-    "coveralls": "cat ./coverage/lcov.info | ./node_modules/.bin/coveralls"
+    "coveralls": "cat ./coverage/lcov.info | ./node_modules/.bin/coveralls",
+    "version": "babel src --out-dir npm"
   },
   "author": "Daniel Cook",
   "license": "MIT",
   "devDependencies": {
     "@vue/test-utils": "^1.0.0-beta.12",
     "axios": "^0.18.0",
+    "babel-cli": "^6.26.0",
     "babel-core": "^6.26.0",
     "babel-jest": "^23.0.0-alpha.0",
     "babel-plugin-transform-object-rest-spread": "^6.26.0",