Retry when `bulk_index` times out
Retry when `bulk_index` times out

We have logged over 425k events for `Faraday::TimeoutError` which come
from the `bulk_index` method timing out. There appears to be no pattern
as to what causes this, so we will retry the indexing 10 times if one
attempt times out.

alphagov/rummager,alphagov/rummager