* Remove testing for rethinkdb, mongodb, and Py3.5
* Add first tests
* Add validation
* Add command to start the ABCI Server
* Reuse existing MongoDB Connection class
* Use DuplicateTransaction
* Test only tendermint
* Update travis scripts
* Fix pep8 errors
* Update Makefile
* Add SSL support for MongoDB connections
* Tests for TLS connectivity and other fixes
* Add test for ssl parameters
* Add test for AuthenticationError
* Cleanup branch
* Split env vars as per @r-marques suggestion
* Remove SSL_ENABLED and use BIGCHAINDB_DATABASE_SSL instead
* Changes as per comments from @r-marques
* Remove redundant tests
* Test for ConfigurationError
* Added replicaset name to bigchaindb config
* changed travis replSet to match bigchaindb default
* Updated initialize_replica_set
It now initializes the replica set with the name provided by the
bigchaindb config file.
* initialize_replica_set is now called when creating a mongodb connection.
This way we are sure that a replica set exists when we return a
connection.
* Moved the initialize replica set logic to the connection.
* update the config documentation
