Transaction Resubmit Policy

[gakonst]

Is your feature request related to a problem? Please describe.

Currently if a transaction gets submitted with too low gas price, it can potentially get stuck in the mempool. It would be nice if we could work around that by automatically bumping its fee according to some policy which is defined by the caller.

Describe the solution you'd like

A similar implementation to PendingTransaction which takes the re-submission policy as a constructor argument. Its Future implementation would then try to get the receipt, and if the receipt returns an error, instead of directly queuing up the receipt check, it'd first re-submit the transaction with a new gas price, according to the policy.

Note: h/t @stonecoldpat the tx hash will change for every bump so you have to adjust it after each submission

[gakonst]

This can probably be implemented as a GasEscalatorMiddleware which maintains state about all pending transactions and re-submits them