Initial spray layer that uses swagger

Currently using swagger-spray which uses annotations to generate swagger doc. Any code generator will need to create these annotated classes like AppMasterService based on an input grammar (which could be swagger like). This class is a simple example of beginning to retrieve AppMaster information from the Master actor. 
Maybe we should add a new interface to get a list of existing application ids. Then we can use this id to query application registeration data, application state, and appmaster address.