Is not possible import external module in conftest.py that use allure's decorators

[RockBomber]

I'm submitting a bug report

Steps to reproduce and a minimal demo of the problem:
Create new PyTest project:
.
./mymodule
./mymodule/_init_.py
./conftest.py
./test_1.py

Content of ./mymodule/_init_.py:

import pytest

@pytest.allure.step('step one')
def step_one():
    pass

Content of ./conftest.py:

from mymodule import step_one

Content of ./test_1.py:

def test_0():
    pass

Then run it: pytest test_1.py --alluredir aresult

You will got an error:

$ pytest test_1.py --alluredir aresult
Traceback (most recent call last):
  File "/home/asdef/.virtualenvs/autotesting/local/lib/python2.7/site-packages/_pytest/config.py", line 373, in _importconftest
    mod = conftestpath.pyimport()
  File "/home/asdef/.virtualenvs/autotesting/local/lib/python2.7/site-packages/py/_path/local.py", line 662, in pyimport
    __import__(modname)
  File "/home/asdef/.virtualenvs/autotesting/local/lib/python2.7/site-packages/_pytest/assertion/rewrite.py", line 215, in load_module
    py.builtin.exec_(co, mod.__dict__)
  File "/home/asdef/.virtualenvs/autotesting/local/lib/python2.7/site-packages/py/_builtin.py", line 221, in exec_
    exec2(obj, globals, locals)
  File "<string>", line 7, in exec2
  File "/home/asdef/Dropbox/Work/Git/PyTestError/conftest.py", line 7, in <module>
    from mymodule import step_one
  File "/home/asdef/Dropbox/Work/Git/PyTestError/mymodule/__init__.py", line 6, in <module>
    @pytest.allure.step('step one')
AttributeError: 'module' object has no attribute 'allure'
ERROR: could not load /home/asdef/Dropbox/Work/Git/PyTestError/conftest.py

Workaround: import mymodule in test_1.py

Expected behavior: successful import of mymodule in conftest.py

Environment:

• Python version: 2.7.8
• Allure version: 2.2.1
• Test framework: pytest@3.1.2
• Allure adaptor: allure-pytest@2.0.0b2