Use root as default name from `tractor.run()`

tests/test_pubsub.py

@@ -161,7 +161,7 @@ def test_multi_actor_subs_arbiter_pub(
 
         async with tractor.open_nursery() as n:
 
-            name = 'arbiter'
+            name = 'root'
 
             if pub_actor == 'streamer':
                 # start the publisher as a daemon

tests/test_rpc.py

@@ -53,7 +53,7 @@ def test_rpc_errors(arb_addr, to_call, testdir):
     exposed_mods, funcname, inside_err = to_call
     subactor_exposed_mods = []
     func_defined = globals().get(funcname, False)
-    subactor_requests_to = 'arbiter'
+    subactor_requests_to = 'root'
     remote_err = tractor.RemoteActorError
 
     # remote module that fails at import time

tractor/_root.py

@@ -185,7 +185,7 @@ def run(
     *args,
 
     # runtime kwargs
-    name: Optional[str] = None,
+    name: Optional[str] = 'root',
     arbiter_addr: Tuple[str, int] = (
         _default_arbiter_host,
         _default_arbiter_port,