执行python freeline.py -h命令时，报错，python版本2.7.10

Traceback (most recent call last):
File "freeline.py", line 7, in
from freeline_core.dispatcher import Dispatcher
File "/Users/qiaojingfei/Desktop/\u5bb6\u653fapp/jz_app_android/freeline/freeline_core/init.py", line 1, in
import build_commands
ModuleNotFoundError: No module named 'build_commands'

Reproduce the failure with Python 2.7.10 by running `python freeline.py -h`. Start with `freeline.py` and `freeline_core/init.py`, where the traceback points to the `build_commands` import; done means the help command runs without the reported ModuleNotFoundError.

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