* Migrate Wercker MJIT tests to Actions
* Support pull request for testing
* Capitalize other jobs too
* Make it a command name for consistency [ci skip]
* Remove wercker.yml
* Add --jit-verbose=2 for debugging
* Install MJIT headers
* Separate install for sudo
* Trigger build
because it's shown as just "master" on a pull request which does not
have the check_branch.master job yet.
"check_branch" would be easier to understand and now we can grep it from
master branch.
