fix: skip skynet example in tests to prevent timeout on slow CI runners

Add early return for "skynet" path in run_example function to avoid
executing the skynet example during test runs, as it is too slow and
causes timeouts on Travis CI bots. Also reduce the kill timer from 5
to 2 seconds in the Test class to fail faster on hanging processes.

util/test.py

@@ -122,7 +122,7 @@ class Test:
       timed_out[0] = True
       p.kill()
 
-    timer = Timer(5, kill_process, [proc])
+    timer = Timer(2, kill_process, [proc])
 
     try:
       timer.start()
@@ -362,6 +362,9 @@ def run_example(path):
   if "animals" in path: return
   if "guess_number" in path: return
 
+  # This one is annoyingly slow.
+  if "skynet" in path: return
+
   run_script(WREN_APP, path, "example")