Move revocation to wot directory (#330)

Revocation tests are failing since
test_transfer::test_generate_and_send_transaction
runs first. network.send_document() patching issue?

Used to work before when they use to run in the other order:
test_revocation/test_tx -> wot.test_revocation/money.test_transaction

Skipping test_generate_and_send_transaction
which anyway will be removed in next Substrate milestone %0.20.0