v1.0.0-alpha.5: Merge pull request #12 from kuzzleio/collectionsOperations

Most of the intended functionalities are implemented, but there is still a lot of work to do. Namely:

• manage offline mode + reconnection
• implement Kuzzle.now() (need a new Kuzzle API route)
• add a new KuzzleFilter object, aiming at helping users to easily construct filters
• add a new KuzzleBulk object, handling bulk requests
• manage requests metadata
• manage subscriptions metadata (need Kuzzle implementation)
• handle multiple subscriptions on the same room
• added collections specific methods: create, delete and truncate