Otherwise test-bot will not behave as expected.

Also: GitHub Actions already sets it.

Ensure that `shellcheck` is run by `brew style` again and fix the
various failures.

If `HOMEBREW_GITHUB_API_TOKEN` is not set and `GITHUB_TOKEN` is: let's
use it. `GITHUB_TOKEN` is a somewhat standard env var to set for
GitHub authentication tokens (e.g. used by `hub`).

- Without `DISPLAY` as an envvar in `bin/brew`, running `brew edit`
  with $EDITOR set to a graphical editor (eg `gedit`), it errored on
  Linux:

```
$ EDITOR=gedit brew edit vim

Editing
/home/linuxbrew/.linuxbrew/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/vim.rb
Unable to init server: Could not connect: Connection refused

(org.gnome.gedit:15470): Gtk-WARNING **: 18:17:07.537: cannot open display:
Error: Failure while executing; `gedit
/home/linuxbrew/.linuxbrew/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/vim.rb`
exited with 1.
```

Fixes #6958.

Also, enable all Bash builtins

Fixes #5692

It's currently unset on Azure Pipelines and Jenkins so let's set it
here for consistency across our ecosystem.

We’re no longer using this for our CI so this is no longer necessary.

Also, migrate `brew tap-new` to use Azure pipelines.

This reverts commit 64a95435.

Use HOMEBREW_CIRCLECI rather than CIRCLECI.
See https://github.com/Homebrew/brew/pull/5402

As of #3870, this is no longer needed.

Additionally, assign HOMEBREW_TEMP based on the host
system (/tmp for Linux, /private/tmp for macOS).

Signed-off-by: lukertty <lukertty@gmail.com>

bin/brew: add 'COLUMNS' and 'LINES' to env variables

Signed-off-by: lukertty <lukertty@gmail.com>

bin/brew will recognize NO_COLOR variable and copy it to
HOMEBREW_NO_COLOR

I've adjusted test-bot in:
https://github.com/Homebrew/homebrew-test-bot/commit/603918939a58a8d6351177fe35f0193b79549dfa
to set CI=1 for Jenkins to make future JENKINS_HOME checks unnecessary.

The only `TRAVIS_*` variable we care about is `TRAVIS_SUDO` so whitelist
that specifically rather than passing through loads of others.

Signed-off-by: xiehuc <xiehuc@gmail.com>

Include SSH_AUTH_SOCK (if set) in the filtered environment to avoid SSH
issues with git.

Fixes #3500