feat(token-authority): sessions
chore(token-authority-server): reordering
chore(token-authority): increase isolation level to SERIALIZABLE
fix(token-authority): fail if there is no valid token to void
refact(token-authority): make split accept a list of tokens
fix(create-tokens): commit before exit
feat(token-client, token-authority-server): switched to new transform command
feat(token-authority): test to prevent double insertion
fix(transfer-purse): move to new transform command