Demo App: Submit a transaction from a Fabric network to HCS

[donaldthibeau]

Feature: Transaction order using the Hedera Consensus Service.

The Hedera Consensus Service is an API which orders messages. The Fabric Peer sends the messageto Hedera. Hedera returns the message, consensus timestamp, running hash, topicID, and sequence number of the message on the topic.

Background
	Given Peers join a common Fabric network
	Then they select a unique topicID
    And they deploy common smart contract logic
	
Example: Submitting a message
	Given a Peer is certified by the Fabric network
	When the Peer submits a message to HCS
	Then the Peer will specify the unique topicID

Example: Returning the ordered message
	Given a Peer has submitted a message
	Then the message will reach consensus
	And a peer will be notified of the message, consensus timestamp, topic's running hash, topic ID, and message's sequence number

Examples: Updating the ledger
    Given a message for a specific topicID has reached consensus
    Then a Peer will associate the message with its smart contract
    And the Peers ledger will update