Commit database after creating oauth_tokens table. Fixes sybrenstuvel#75

This change seems to be required in Python 3.6.0. It works correctly without the db.commit() in 3.5.2 and earlier. Without the commit the first table, oauth_cache_db_version, gets created, but oauth_tokens does not.

flickrapi/tokencache.py

@@ -165,6 +165,8 @@ def create_table(self):
                         user_nsid varchar(64) not null,
                         PRIMARY KEY(api_key, lookup_key))''')
 
+        db.commit()
+
     @property
     def token(self):
         """Return the cached token for this API key, or None if not found."""