Remove ABCI testing fakes [#3147]
Closes #3147 (closed). Remove FakeTendermint and abci_test.FakeNode, replacing them with a compatibility layer on top of the simulator.
Changelog: refactor
Closes #3147 (closed). Remove FakeTendermint and abci_test.FakeNode, replacing them with a compatibility layer on top of the simulator.
Changelog: refactor