Add scripts to (semi)automate release steps

[Treora]

These are roughly the commands from our Creating a Release and Testing a Source Release wiki pages, with the idea to make these procedures easier for a next release.

@tilgovi & @BigBlueHat would you like to improve these scripts, or take another approach to it? Consider it just a draft; feel free to modify substantially or ignore this attempt altogether.

[tilgovi]

This is a great start! I'll check out the branch locally, see if there are any tweaks to make, and maybe try to push up changes to make the verify command interactive. How does that sound?

[Treora]

This is a great start! I'll check out the branch locally, see if there are any tweaks to make, and maybe try to push up changes to make the verify command interactive. How does that sound?

Sounds good! Sorry for my lack of reply before. As said, feel free to build on this or deviate from it.

[tilgovi]

Just tiny questions, but feel free to merge! Thanks, @Treora.

[tilgovi]

We can remove these comments.

[tilgovi]

Do you think we should just download rat here?

[Treora]

I added a commit that downloads RAT, removes comments, removes the sleep pauses too. But I get an error when running this, which looks unrelated to the current change:

$ VERSION=0.2.0 RC=1 ../incubator-annotator/scripts/obtain-rc.sh
…
$ VERSION=0.2.0 RC=1 ../incubator-annotator/scripts/verify-rc.sh
…
tar: apache-annotator-0.2.0-incubating/.git/objects/pack/pack-4e188f5a157612fce8b35a7c799ff1c71b2af004.idx: Cannot open: Permission denied
tar: apache-annotator-0.2.0-incubating/.git/objects/pack/pack-4e188f5a157612fce8b35a7c799ff1c71b2af004.pack: Cannot open: Permission denied

Could you perhaps check if it works for you, @tilgovi (or anyone)?

[tilgovi]

@Treora I would be fine to drop the RAT steps. It feels strange to download a jar and leave it on the machine. Unless we download it to the current directory.

[tilgovi]

As for the error, something must be wrong with the permissions on the git directory that gets created.

I am thinking that initializing a git repository inside the archive is a bit surprising. It definitely looks wrong to have a .git directory. I can make a PR to use git archive instead of git clone. It will just make the steps to compare the archive against the tag a little bit different.