Avoid "GitlabClaBotLoggingBucket already exists"

[maoo]

The serverless deploy command always fails (except the first time) with the error:

  An error occurred: GitlabClaBotLoggingBucket - finos-gitlab-cla-bot-logs already exists.

Using https://www.npmjs.com/package/serverless-plugin-existing-s3 to work around the issue

[sehaswell]

Interesting that you have experienced this issue - my serverless seemed not to have trouble tearing down or replacing the old bucket.

I'm not sure I understand this fix - it looks to me like you're listing events on an existing bucket as something that should trigger the lambda. If you do this, does it not perpetually trigger itself?

What now happens on first deploy? And on teardown?
The bucket is no longer part of this serverless deployment so it won't be created or removed with it. If we go with this then the README needs instructions to create and manage one's own bucket.

What we do on this PR might resolve #31

[maoo]

Good points. I haven't tested first deploy or teardown, but seems that the plugin aims to address issues described on #31 . Happy to keep this PR open until that issue is tackled!