core: Use a mixer mock in tests
core: Use a mixer mock in tests

vrs01/mopidy,pacificIT/mopidy,adamcik/mopidy,glogiotatidis/mopidy,rawdlite/mopidy,ZenithDK/mopidy,vrs01/mopidy,pacificIT/mopidy,ZenithDK/mopidy,SuperStarPL/mopidy,jmarsik/mopidy,mokieyue/mopidy,ZenithDK/mopidy,ali/mopidy,rawdlite/mopidy,swak/mopidy,SuperStarPL/mopidy,swak/mopidy,glogiotatidis/mopidy,bacontext/mopidy,jmarsik/mopidy,bencevans/mopidy,jodal/mopidy,glogiotatidis/mopidy,jcass77/mopidy,quartz55/mopidy,mopidy/mopidy,pacificIT/mopidy,mokieyue/mopidy,hkariti/mopidy,mokieyue/mopidy,hkariti/mopidy,dbrgn/mopidy,quartz55/mopidy,jcass77/mopidy,SuperStarPL/mopidy,quartz55/mopidy,swak/mopidy,bacontext/mopidy,mopidy/mopidy,quartz55/mopidy,jodal/mopidy,dbrgn/mopidy,bencevans/mopidy,mopidy/mopidy,adamcik/mopidy,dbrgn/mopidy,ali/mopidy,vrs01/mopidy,swak/mopidy,diandiankan/mopidy,bencevans/mopidy,jcass77/mopidy,ali/mopidy,kingosticks/mopidy,diandiankan/mopidy,rawdlite/mopidy,dbrgn/mopidy,jmarsik/mopidy,diandiankan/mopidy,tkem/mopidy,tkem/mopidy,jodal/mopidy,ZenithDK/mopidy,tkem/mopidy,kingosticks/mopidy,bacontext/mopidy,rawdlite/mopidy,bacontext/mopidy,vrs01/mopidy,jmarsik/mopidy,pacificIT/mopidy,hkariti/mopidy,mokieyue/mopidy,kingosticks/mopidy,SuperStarPL/mopidy,glogiotatidis/mopidy,adamcik/mopidy,diandiankan/mopidy,ali/mopidy,bencevans/mopidy,hkariti/mopidy,tkem/mopidy