chore(package): update microbundle to version 0.5.1

Closes #6

Author: greenkeeper[bot]

package.json

@@ -33,7 +33,7 @@
   "devDependencies": {
     "eslint": "^4.13.1",
     "eslint-config-developit": "^1.1.1",
-    "microbundle": "^0.4.1"
+    "microbundle": "^0.5.1"
   },
   "dependencies": {
     "magic-string": "^0.22.4"