Merge pull request #4 from zumba/es-5.2-support

Adding support to ES 5.x

Fixed unit test to reference configuration index mapping properly.

Merge pull request #3 from zumba/alias-strategy

Add an alias strategy for primary index.

Merge pull request #2 from polyfractal/preference_primary

GET requests should go to primary shard

Added PHP requirement for composer.

Added license. [skip ci]

Correct spelling on index plural...