Merge pull request #297 from facebookincubator/v0.2

Update paper

docs/_data/promo.yml

@@ -13,5 +13,5 @@
     href: docs/quick_start.html#python-api
     text: Get started in Python
   - type: button
-    href: static/prophet_paper_20170113.pdf
+    href: static/prophet_paper_preprint.pdf
     text: Read the paper