Support Eleastic search as a SAS backend

[Glen Robson]

To aid deployment to AWS we are planning to add Elastic search as a backend. This should allow the automated deployment of the SAS code without overwritting the annotation data. The AWS elastic search details are here:

https://aws.amazon.com/elasticsearch-service/

To do check list:

• Setup docker-compose instance with Elastic Search and SAS
• Clean up adapter interface (look at splitting Manifest, Annotation into separate classes)
• Implement Elastic Search adapter
• Add ElasticSearch integration tests
• Look at AWS ElasticSearch and deployment implications
• Implement auto deployment to AWS