Adds move_to on the index

[nunomaduro]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Need Doc update	no

Describe your change

This Pull Request adds the move method on the index. Usage:

index = client.init_index('name');
index.move('new_name')
index.get_settings() # Get the settings of the `new_name` index

[nunomaduro]

Question for the team: Should I add the @deprecated tag into the client::move_index method?

[julienbourdeau]

Yes I think you can deprecate the move on client, I removed it from php v2 👌

[nunomaduro]

Closing this issue since it's not being implemented anymore.