ENH: Add a tool for release authors and PRs.

[charris]

Add the script tools/announce.py to generate the author and pull request
lists needed in release announcements. Some bits of this are taken from
the scipy gh_list.py and authors.py tools.

Usage:

$ ./tools/announce.py <github_user> <github_password> <revision_range>

The output is utf8 rst.

[ci skip]

[rgommers]

Such a script is useful, but I'm not inclined to put in my GitHub password for a script with a dependency I don't know about ......

It seems unnecessary to use a username/password here, all info is freely available (the scipy scripts don't need it either).

[pv]

It's probably a good idea to specify which of the several github API
libraries is required. As @rgommers notes, the user/password is not
needed to access the relevant data (and it's bad mojo to specify it on
command line, should at least use raw_input for that). The various
Github API libraries probably do permit anonymous access mode.

[pv]

If you want to work around API rate limits, it's probably better to use API tokens https://github.com/settings/tokens instead of user+password. The API tokens can be fully read-only.

[charris]

Agree about the password, but rate limiting was a problem as I don't read all the data down in a big blob but PR by PR. The 300+ needed PRs aren't tagged, Entering a hidden password interfered with output redirection. What I really wanted was ssh communication. @pv I'll take a look at tokens, I went with basic authentication to start.

EDIT: The anonymous rate limit of 50/hour is pretty severe, I hit it on the first test.

[rgommers]

@charris I don't quite understand the advantage of retrieving PRs over using the commit history?

[charris]

@rgommers You get the PR title among other things. For an extended commit log, it would also be possible to retrieve the PR description. I also think it would good to improve release documentation in the long run and use it rather than the current release notes format. Our work is organized by PRs rather than commits so it makes sense to use them and the links provide a nice way for folks to get more detail on the PR.

In any case, scipy has done the same for the last couple of releases.

[charris]

Updated to use a github token. I feel much better about that...

[charris]

@rgommers Also, note that it is possible to edit the PR titles and descriptions to improve or correct them, something that is hard to do with merged commits.

[charris]

Putting this in as I will want to use it.