[gnome-music] (8 commits) Non-fast-forward update to branch wip/jfelder/mpris-cleanup

[Jean Felder <jfelder src gnome org>]

The branch 'wip/jfelder/mpris-cleanup' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  c0e9418... player: Remove volume logic
  f0cfbd7... mpris: Change naming convention to snake_case
  38332ff... mpris: Move dbus connection logic to DBusInterface
  af6ccf7... mpris: Handle signals emissions internally
  23ce360... mpris: Make app attribute internal
  5d84be1... mpris: Make player attribute internal
  f916ee0... mpris: Make player_toolbar attribute internal
  7a9632e... mpris: Update copyright information

Commits added to the branch:

  0059bea... player: Remove volume logic
  96bf67c... mpris: Change naming convention to snake_case
  7e42070... mpris: Move dbus connection logic to DBusInterface
  9c5f434... mpris: Handle signals emissions internally
  951ac71... mpris: Make app attribute internal
  111abf6... mpris: Make player attribute internal
  85775d8... mpris: Make player_toolbar attribute internal
  fbd9f8e... mpris: Update copyright information