Updates cloud instances data management
Abstraction Improvements & Code Refactoring

  This commit changes the basic way of how ankus stores the abstraction of
  node(s) which results in lot of code refactoring.

  Users can now change the deployment information in the config file and
  will be able to use `deploy --reload` to apply the deployment changes,
  instead of using `deploy --add-nodes --count 2 --roles worker` (or)
  `deploy --add-nodes --hosts blah.ops.com blah2.ops.com --roles worker`.
  Also, `--reload` is designed to be idempotent in nature.
Fixes AWS deployments with new abstraction layer
Fixes RackSpace cloud deployments to support new data abstraction layer
Version bump 0.2.7
Adds hadoop non-ha deployment scenario
Fixes Local deployments with new abstraction layer
Merge pull request #33 from ashrithr/feature/data_overhaul

Feature/data overhaul