Added rake task to create an index with the given template
Added rake task to set alias to a specific index
Refactored and fixed setting of index alias.

Due to the nature of ElasticSearch's non-standard multiline JSON the Eson client is used to remove and add aliases instead of generating the request with hashes by the rake task.
Merge pull request #7 from Asquera/feature-update-mapping-with-new-index

Rake tasks added to enable update index with an alias