post tags are shown as "object"

[tgaff]

After creating a post one can see that the posts tags, regardless of what was entered are shown as "object".

Steps to reproduce:

1. Create a new post
2. When you press publish, enter some tags (quantity doesn't seem to matter)
3. Finish publishing the post
4. Visit the root route
5. Observe the newest post has tags "object object"

Expected behavior:

1. the tags one types are displayed in the article summary

[tgaff]

Hint: 1

Watch the tags box closely when you're publishing the article.