Update to work with 0.90.3
Closes #8.
Consistency between documentation and code:

* `bulk_size` and `drop_threshold` are now read from the index settings
* default type value is now `page` as stated in README file

Thanks to @javanna and @bkirwi

Closes #6.
Add integration test
Closes #9.
prepare release elasticsearch-river-wikipedia-1.2.0
prepare for next development iteration