[macports-base] branch travis-ci updated (7a6956c3 -> adabd58d)

[Clemens Lang]

Clemens Lang (neverpanic) pushed a change to branch travis-ci
in repository macports-base.

    from 7a6956c3 ci: Add deployment for macOS 11
     new 78778e06 ci: Upload new version, old one is now immutable
     new adabd58d ci: Add github workflow to publish build env

The 2 revisions listed above as "new" are entirely new to this
repository and will be described in separate emails.  The revisions
listed as "add" were already present in the repository and have only
been added to this reference.


Summary of changes:
 .bintray.json                        |  4 +-
 .github/workflows/prepare-ci-env.yml | 74 ++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+), 2 deletions(-)
 create mode 100644 .github/workflows/prepare-ci-env.yml