add launcher dev

dev.py

@@ -1,6 +1,9 @@
+import sys
 from pathlib import Path
 
+sys.argv.append('--dev')
+
 from flandre.launcher import launch_from_file
 
 if __name__ == '__main__':
-    launch_from_file(Path(__file__).parent / 'gui.toml')
+    launch_from_file(Path(__file__).parent / 'dev.toml')

dev.toml

@@ -0,0 +1,2 @@
+[MainUI]
+[ImageCV]

flandre/nodes/Midi.py

@@ -1,6 +1,5 @@
 import logging
 from threading import Thread
-from unittest import case
 
 import mido
 import zmq