- show synopsis when 'hub delete' is called without the name of a repo
- printing information about missing rights in the access token in case
  repo deletion fails with HTTP 403

- no more HUB_UNSAFE_DELETE environment variable, use -y/--yes now
- do not check for project before deletion
- only ask for y/n confirmation when deleting

Also, split the pull request template with two newlines in between for
compatibility with GitHub web interface.

Fixes #1714

Closes #1731

Fixes #1748

Set slice length to known number of args

pull-request: Hide Signed-off-by

The previous approach would make one HTTP request per every release
until it found one with a matching tag. Now it fetches in bulk.

Fixes #1747

Fixes #1724.

This patch omits the "Signed-off-by:" line coming from pull requests created
out of single commit messages. This way the user does not need to manually
remove their email address from the PR description.

Not introducing a flag for this as it applies to only one case (single-commit
diff between heads, as well as no -m/-f/-i specified).

Meta: sending this PR with the patched build, my Signed-off-by line is removed
automatically from the PR message.
Signed-off-by: NAhmet Alp Balkan <ahmetb@google.com>

Closes #1740

Add milestone to PR by name instead of number

[RFC] Make fork --remote-name=origin rename origin

If user passes `origin` as the remote name
pointing to forked repository, it's likely
she wants to rename origin as upstream.

[ci skip]

Add install instructions for scoop on Windows

When querying `foo/bar` repo redirects elsewhere, assume that `foo/bar`
is available. Fixes #1685

Fixes #1549