Add repository to package.json (aweary#27)

helpful for:
* ```npm repo```
* going from npm to github

Author: chrishelgert

package.json

@@ -5,6 +5,10 @@
   "main": "dist/tinytime.js",
   "umd:main": "dist/tinytime.umd.js",
   "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/aweary/tinytime"
+  },
   "scripts": {
     "rollup:cjs": "NODE_ENV=production rollup -c rollup.config.js -m -f cjs -n $npm_package_amdName $npm_package_jsnext_main -o $npm_package_main",
     "rollup:umd": "NODE_ENV=production rollup -c rollup.config.js -m -f umd -n $npm_package_amdName $npm_package_jsnext_main -o dist/tinytime.umd.js",