Juno specs

• Make anti affinity working via server groups
• Append to a remote existing file
• Plugin for CDH with Cloudera Manager
• Specification for integration Sahara with Ceilometer
• Store Sahara configuration in cluster properties
• Security groups management in Sahara
• Move the EDP examples from the sahara-extra repo to sahara
• [EDP] Refactor job manager to support multiple implementations
• [EDP] Add a Spark job type (instead of overloading Java)
• [EDP] Add an engine for a Spark standalone deployment
• [EDP] Using trust delegation for Swift authentication
• Improve error handling for provisioning operations
• Move Sahara REST API samples from /etc to docs