Description: This effort is related to this pull request. On each new pull request, automatically post a comment with the following contents:

Thanks a lot for your contribution to the Apache Flink project. I'm the @flinkbot. I help the community
to review your pull request. We will use this comment to track the progress of the review.


# Review Progress

* [ ] 1. The [contribution] is well-described.
* [ ] 2. There is [consensus] that the contribution should go into to Flink.
* [ ] 3. [Does not need specific [attention] | Needs specific attention for X | Has attention for X by Y]
* [ ] 4. The [architecture] is sound.
* [ ] 5. Overall code [quality] is good.

Please see the [Pull Request Review Guide](https://flink.apache.org/reviewing-prs.html) if you have questions about the review process.

Check each subsequent comment for a mention:

• @flinkbot contribution approve: Update original comment and put the author as a approver of a review
• @flinkbot contribution disapprove: Remove author as an approver
• .. add approve / disapprove for contribution, consensus, architecture, architecture
• For attention @fhueske add the name to the list of "attention payers".

After a series of comments, the review progress could for example look like this:

# Review Progress

* [ ] 1. The [contribution] is well-described.
    - Approved by @twalthr [PMC], @johndoe 
* [ ] 2. There is [consensus] that the contribution should go into to Flink.
* [ ] 3. [Does not need specific [attention] | Needs specific attention for X | Has attention for X by Y]
* [ ] 4. The [architecture] is sound.
    - Approved by @pnowojski [PMC], @johndoe
* [ ] 5. Overall code [quality] is good.

Please see the [Pull Request Review Guide](https://flink.apache.org/reviewing-prs.html) if you have questions about the review process.

• could it add the mentioned person to reviewers, when using @flinkbot attention
• could it tick the boxes?
• support approve all
• if the bot is mentioned in a thread without a tracking message: post one (limit to configured repo)
• attention-payers can tell the bot that they approve.
• allow multiple approvals, such as @flinkbot approve description consensus architecture +2
• approve all up to a certain point, such as @flinkbot approve-until architecture.
• Execute jebsen tests
• Dynamically query list of contributors from GH
• Flinkbot does not process mentions in reviews apache/flink#7670 (review)
• Error with . apache/flink#7725
• Add attention payer to reviewer
• forbid reviews by the PR author
• approved / pending / rejected states for each step
• detect special pull requests hotfixes, documentation only, new contributors
• BUG: don't re-request reviews once review is done: apache/flink#8210

• For the PR bot, put a label whether a PR is ready to merge
• Flink community metrics
• Pull requests dashboard
• Automatic labeling of pull requests (into project components)
• Automatic merging of pull requests by the bot IF:
  • all review items have been approved
  • travis is green
  • a committer has labeled the PR to be merged

MIT License (see license file).