v0.12.0: SEP-31 Support

Features

• Full SEP-31 support. See the documentation on the integration constructs provided
• Updates to SEP-12. (See #588, #653, #669, #674, and #681)

Breaking Changes

• Moved DepositIntegration.poll_pending_deposits() to RailsIntegration.poll_pending_deposits()
• Replaced WithdrawalIntegration.process_withdrawal() with RailsIntegration.execute_outgoing_transaction()
  • SEP-6 and 24 transactions uses this function now instead of process_withdrawal
• Polaris no longer calls the registered_fee_function except when requests to /fee are made.
  • The anchor is now responsible for calculating the fee in poll_pending_deposits() and execute_outgoing_transaction()
• Removed Transaction.external_extra
• Removed Transaction.external_extra_text

DB Migrations

Added SEP-31 columns:

• Asset.sep31_enabled: a boolean for whether the asset can be received via SEP-31
• Asset.send_fee_percent: the 0-100 percentage value for fees on a transaction
• Asset.send_fee_fixed: the fixed fee charged per transaction
• Asset.send_min_amount: the minimum amount the anchor accepts in a transaction
• Asset.send_max_amount: the maximum amount the anchor accepts in a transaction
• Transaction.required_info_update: a text field for describing required updates to the transaction
• Transaction.required_info_message: a text field for a human-readable message about updates to the transaction
• Transaction.send_memo: the memo used when making the Stellar payment to the receiving anchor
• Transaction.send_memo_type: the memo type of the memo used
• Transaction.send_anchor_account: the anchor's Stellar address for receiving payments

Bug Fixes

• Fixed Polaris' validate_language() function to only allow supported languages
  • prior to this release Polaris would not automatically return 400 for requests in languages not supported by the anchor