Merge pull request #152 from scrapinghub/og-product

Add "product" namespace support for opengraph

Author: jakubwasikowski

extruct/opengraph.py

@@ -11,6 +11,8 @@
     'article': 'http://ogp.me/ns/article#',
     'book': 'http://ogp.me/ns/book#',
     'profile': 'http://ogp.me/ns/profile#',
+    # non-standard but seen in the wild
+    'product': 'http://ogp.me/ns/product#',  # ~10% of product pages with OG
 }