tests: test to ensure each plugin listed in the plugin matrix exists
tests: test to ensure each plugin listed in the plugin matrix exists

back-to/streamlink,back-to/streamlink,chhe/streamlink,beardypig/streamlink,melmorabity/streamlink,melmorabity/streamlink,bastimeyer/streamlink,gravyboat/streamlink,javiercantero/streamlink,wlerin/streamlink,streamlink/streamlink,beardypig/streamlink,wlerin/streamlink,javiercantero/streamlink,bastimeyer/streamlink,chhe/streamlink,streamlink/streamlink,gravyboat/streamlink