[libgit2-glib] Created tag v0.28.0

[Alberto Fanjul <albfan src gnome org>]

The signed tag 'v0.28.0' was created.

Tagger: Alberto Fanjul <albertofanjul gmail com>
Date: 1556078147 +0200

    Tag 0.28.0

Changes since the last tag 'v0.27.8':

Alan Knowles (5):
      Add push operation
      fix GgitDiffLineCallback signature
      git_merge_trees: ancestor_tree can be null
      Add git_repository_merge_base
      Add ggit_repository_merge

Alberto Fanjul (4):
      Revert "Added·push·support"
      Fix documentation
      Standardize push callbacks
      Release 0.28.0

Christian Hergert (1):
      submodule: fix invalid g_return_val_if_fail()

Corentin Noël (1):
      oid: Annotate the byte array when getting raw data

Elliott Sales de Andrade (1):
      Update use of meson's python module.

Ignazio Sgalmuzzo (1):
      Added·push·support

Ignazio·Sgalmuzzo· (1):
      Added·push·support

Tom Schoonjans (2):
      meson: use -Bsymbolic-functions only when supported
      meson: add support for macOS dylib versioning

maxice8 (1):
      Compatibility with libgit2 0.28