don't require write perms on the target repo

[TomasTomecek]

Related #148

• don't set or create labels if you don't have the permission
• create the PR from fork, not on the upstream repo (also tracked in updates to creating a release PR #148)
• closing the issue (which wasn't created by the bot) @lachmanfrantisek
• anything else?

Okay, there is a big problem here: the bot needs to push out the git tag. And that requires a write permission.

[lachmanfrantisek]

Closing the issue?

[TomasTomecek]

We already have a ton of code for this in ogr