Encode TimeoutExpired texts

If there's a timeout, the error will have to be decoded because it's assumed to be encoded. This way we prevent crashes in the manager due to `AttributeError: 'str' object has no attribute 'decode'`

sisyphus/aws_batch_engine.py

@@ -94,7 +94,7 @@ def system_call(self, command, send_to_stdin=None):
             p = subprocess.run(system_command, input=send_to_stdin, capture_output=True, timeout=30)
         except subprocess.TimeoutExpired:
             logging.warning("Timeout expired for command: %s" % " ".join(system_command))
-            return [], ["TimeoutExpired"], -1
+            return [], ["TimeoutExpired".encode()], -1
 
         def fix_output(o):
             """

sisyphus/load_sharing_facility_engine.py

@@ -62,7 +62,7 @@ def system_call(self, command, send_to_stdin=None):
             p = subprocess.run(system_command, input=send_to_stdin, capture_output=True, timeout=30)
         except subprocess.TimeoutExpired:
             logging.warning("Timeout expired for command: %s" % " ".join(system_command))
-            return [], ["TimeoutExpired"], -1
+            return [], ["TimeoutExpired".encode()], -1
 
         def fix_output(o):
             # split output and drop last empty line

sisyphus/simple_linux_utility_for_resource_management_engine.py

@@ -100,7 +100,7 @@ def system_call(self, command, send_to_stdin=None):
             p = subprocess.run(system_command, input=send_to_stdin, capture_output=True, timeout=30)
         except subprocess.TimeoutExpired:
             logging.warning("Timeout expired for command: %s" % " ".join(system_command))
-            return [], ["TimeoutExpired"], -1
+            return [], ["TimeoutExpired".encode()], -1
 
         def fix_output(o):
             """

sisyphus/son_of_grid_engine.py

@@ -101,7 +101,7 @@ def system_call(self, command, send_to_stdin=None):
             p = subprocess.run(system_command, input=send_to_stdin, capture_output=True, timeout=30)
         except subprocess.TimeoutExpired:
             logging.warning("Timeout expired for command: %s" % " ".join(system_command))
-            return [], ["TimeoutExpired"], -1
+            return [], ["TimeoutExpired".encode()], -1
 
         def fix_output(o):
             """