Use one task because travis env does not have multiple cores

test/test_task.py

@@ -435,7 +435,7 @@ def testNoWait(self):
             with open('test.sos', 'w') as tst:
                 tst.write(r'''
 [10]
-input: for_each=[{'a': range(3)}]
+input: for_each=[{'a': range(1)}]
 
 task: concurrent=True
 run: expand=True