Bump Mempool version

Bump version to 2.3.0

We need to determine a way if there is existing mempool db and delete it.

According to wiz the new db is not compatible and will need to be erased first. before installing.

@dammkewl maybe there is a creative way to determine some logic if 2.2.x is installed and delete that db before installing/upgrading dojo.

Deleting the existing mempool db no longer necessary.