Do not invoke GitHub API update operations needlessly

[vitvly]

Description

Type: Bug GitHub comments should only be updated once after any relevant input changes.

Expected behavior

GitHub comment is not updated unless:

• there is a change in the state of a bounty or associated contract (bounty contract mined, waiting for confirmation, paid, etc.)
• contributor's payout address is not set
• ETH or token balance changes

Actual behavior

If a PR for an issue with a bounty has been merged, but the contributor has no Ethereum address set in OpenBounty, scheduler's self-sign-bounty thread will attempt to repeatedly update a GitHub comment with text "Pending user to save ETH address", although just one update is enough.

Steps to reproduce

• Register a contributor's account on SOB
• Do not set Ethereum account address for contributor
• Create an issue with a bounty from an owner's account
• Post and merge a PR from that contributor's account
• Check that OpenBounty bot comment is being updated each minute with the same text "Pending user to save ETH address"

Solution

Store an additional flag inside issue comment hash (comment_hash field in issue_comment table). Currently the hash is generated based on a tuple owner, repo, issue_number, eth_balance. Include an additional flag from the enumeration address_not_set, pending_confirmation, paid. Always generate a hash based on this data before posting a GitHub comment update and proceed only if generated hash differs from the one stored in database.

[martinklepsch]

@arash009 did we get an update from GitHub whether our changes have already reduced the issue sufficiently?

[arash009]

The main concern at the time was that one issue that was doing the non-stop repeated calls which we stopped straight away. That was confirmed.

Once this is implemented we will go back to them to recheck our usage.