Update README.md
Merge pull request #22 from clicktravel-steffan/master

FC-73 Keep processing messages if 5xx error on SQS receive
Made CloudSearchEngine make use of latest AWS SDK to make signed requests to CloudSearch endpoints.
Added logger to report when we're unable to cache the endpoints.
Merge pull request #23 from clicktravel-basharat/master

Made CloudSearchEngine make use of latest AWS SDK to make signed requests to CloudSearch endpoints.
Log non-interrupt exceptions and re-throw to give feedback
Merge pull request #24 from clicktravel-basharat/master

Log non-interrupt exceptions and re-throw to give feedback