Create CorsixTH

[lewri]

CorsixTH will now provide an AppImage of our software, hosted through the official repository.

Edit: The test spat out some ALSA lib errors, this is believed to be down to the test enviornment and not our build

ALSA lib confmisc.c:855:(parse_card) cannot find card '0'
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_card_inum returned error: No such file or directory
ALSA lib confmisc.c:422:(snd_func_concat) error evaluating strings
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1334:(snd_func_refer) error evaluating name
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5701:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2664:(snd_pcm_open_noupdate) Unknown PCM default
Notice: Audio system could not initialise (SDL error: ALSA: Couldn't open audio device: No such file or directory)

[probonopd]

Most likely, since the test is running on a headless server. We need to find a way to "fake" ALSA in the test.

[lewri]

NB: We're due to shortly release 0.69.0 next week. Let me know if this pr needs a bump at all (and how) to accommodate that.

[lewri]

@probonopd do you need anything else from me for this?