* Run Python2.6 unit tests on Github Actions
* Skip url tests on Python 2.6 to reduce waiting times
* Skip foreground background tests on Python 2.6 to reduce waiting times
* Removed references to Travis in the documentation
* Deleted install_patchelf.sh (can be installed from repo on CentOS 6)

Updated actions where needed

Style and documentation tests take just a few minutes
to run. Since in Github actions one can't restart a single
job but needs to restart an entire workflow, here we group
tests with similar duration together.

- [x] remove master from github actions
- [x] remove master from .travis.yml
- [x] make `develop` the default branch for `spack ci`

* Move flake8 tests on Github Actions

* Move shell test to Github Actions

* Moved documentation build to Github Action

* Don't run coverage on Python 2.6

Since we get connection errors consistently on Travis
when trying to upload coverage results for Python 2.6,
avoid computing coverage entirely to speed-up tests.

Nightly builds with MacOS started failing again
due to an upgrade of the default virtual environment
that now uses Python 3.8

This makes us hit #14102 and every build fails. This
commit should be reverted along with the fix to #14102.

Ci is currently failing on brew update with the error:
```
Error: Cannot install bazelisk because conflicting formulae are installed.
  bazel: because Bazelisk replaces the bazel binary

Please `brew unlink bazel` before continuing.

Unlinking removes a formula's symlinks from /usr/local. You can
link the formula again after the install finishes. You can --force this
install, but the build may fail or cause obscure side effects in the
resulting software.
```
Avoiding:
```
$ brew update
$ brew upgrade
```
solves the issue by preventing the risk of conflicting formulae

* Run Python2.6 unit tests on Github Actions
* Skip url tests on Python 2.6 to reduce waiting times
* Skip foreground background tests on Python 2.6 to reduce waiting times
* Removed references to Travis in the documentation
* Deleted install_patchelf.sh (can be installed from repo on CentOS 6)

Updated actions where needed

Style and documentation tests take just a few minutes
to run. Since in Github actions one can't restart a single
job but needs to restart an entire workflow, here we group
tests with similar duration together.

* MacOS build tests

- Run on PR that modify the YAML file of the workflow
- Don't clone Spack, since we are in the Spack repo now

* Try to add opengl to configuration to build jupyter

* fixup

- [x] remove master from github actions
- [x] remove master from .travis.yml
- [x] make `develop` the default branch for `spack ci`

* Move flake8 tests on Github Actions

* Move shell test to Github Actions

* Moved documentation build to Github Action

* Don't run coverage on Python 2.6

Since we get connection errors consistently on Travis
when trying to upload coverage results for Python 2.6,
avoid computing coverage entirely to speed-up tests.

* Added unit tests to Github Actions

* Set user e-mail and name for git tests to succeed

* Simplify setup.sh logic

* Replicate Travis script on Github Actions

* Update flags since '.' is not allowed

* Added badge, simplified workflow

* Remove pinning of coverage

* Remove unit tests run on Github Actions from Travis

* Skip failing test on MacOS

* Update setup-python action and unpin coverage

The -u option allows to update the current head,
so tests won't fail if we are on develop

check if failures ares actually a real timeout or an error that
just causes a hang.

All GitHub actions provide two cores. Just make sure this does not
get oversubscribed with potentially visible additional physical
cores.

- Remove macos tests from travis
- Add macos tests in github actions.

Add nightly builds for popular and commonly used packages on
macOS that should improve the onramp user experience if
working well.

* Add --version arg to spack python command
* Add `spack debug report` command

* Check on Python versions uses action/checkout@v2
* Update the apt cache before installing system packages

I usually want to look at the Travis CI output, but I currently have to
scroll down to see it. This renames checks to be a bit shorter and more
consistent with Travis's naming, and also so that actions appear lower
than travis and codecov in the list of checks.

This PR moves build smoke tests from TravisCI and migrates them to Github Actions. The result is that build tests are performed in parallel with unit tests and they don't hog additional resources on Travis. The workflow will not run if a PR only changes packages in the built-in repository, but will always run on pushes to develop or master.

* Removed build tests from Travis and passed them to Github Actions
* Store ~/.ccache in Github Actions cache
* Add filters on paths and make sure this workflow don't run
* Use paths-ignore and exclude only files in the built-in repo
* Added a badge to README.md

This commit removes the `python_version.py` unit test module
and the vendored dependencies `pyqver2.py` and `pyqver3.py`.
It substitutes them with an equivalent check done using
`vermin` that is run as a separate workflow via Github Actions.

This allows us to delete 2 vendored dependencies that are unmaintained
and substitutes them with a maintained tool.

Also, updates the list of vendored dependencies.

This reverts commit 54e3bc31.

Use `spack pkg changed` and `spack maintainers` to figure out which
packages changed and who their maintainers are in a PR.

Add any maintainers to the PR as reviewers.