Use latest aioca alpha

Author: AlexanderWells-diamond

setup.cfg

@@ -55,7 +55,7 @@ dev =
     sphinx-rtd-theme ==1.0.0
     sphinx-rtd-theme-github-versions ==1.1
     pytest-asyncio
-    aioca >=1.6
+    aioca >=2.0a3
     cothread; sys_platform != "win32"
     p4p>=4.2.1a1