Dummy Distributed Data Store for testing replication

Dummy Distributed Data Store for testing replication

To use this run a real instance of the controller on your laptop.
Modify the module-shards.conf to replicate modules to member-2 or
member-2 and member-3 as neccessary.

Then run the dummy datastore.

For example,

   java -jar ./target/sal-dummy-distributed-datastore-1.2.0-SNAPSHOT-allinone.jar -member-name member-2 -cause-trouble -drop-replies -max-delay-millis 500

Runs the dummy datastore as member-2. Will cause failures including dropped replies and when it does reply may cause a random delay of upto
500 millis

This will start of the dummy datastore which will then spawn dummy shard actors which will listen to the RequestVote
and AppendEntries messages. For RequestVote messages it will always respond with a positive vote and for AppendEntries
it will put a sleep for a randomized interval upto the max delay.

Change-Id: Ib618365f12bcc714fcf45e29051f8796f798a361
Signed-off-by: Moiz Raja <moraja@cisco.com>