Remove default index shards/replicas counts

Fixes https://github.com/sksamuel/elastic4s/issues/219.

I have a couple of questions/comments about this - see them in the diff.
Sometimes I set to one shard because  travis  used to moan in the early
days. If build staya green ut can go.
On 2 Oct 2014 13:02, "Ben Symonds" <notifications@github.com> wrote:

> In src/test/resources/json/createindex/createindex_mappings.json:
>
> > @@ -1,8 +1,7 @@
> >  {
> >      "settings": {
> >          "index": {
> > -            "number_of_shards": 2,
> > -            "number_of_replicas": 1
> > +            "number_of_shards": 2
>
> A lot of the tests *explicitly* set shards in their index creation, even
> thought they aren't really concerned with it (e.g. in this case it's about
> setting mappings). So it might be nicer to just remove that explicit
> shards call completely. What do you think?
>
> —
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> <https://github.com/sksamuel/elastic4s/pull/220/files#r18334644>.
>