setUp method in testPolicy test case doesn't catch pipe errors

[Whissi]

I run into the following test failure:

======================================================================
ERROR: testPolicy (testpolicy.PolicyTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/var/tmp/portage/dev-python/pymilter-1.0.5/work/pymilter-pymilter-1.0.5/testpolicy.py", line 26, in testPolicy
    with MTAPolicy('[email protected]',conf=self.config) as p:
  File "/var/tmp/portage/dev-python/pymilter-1.0.5/work/pymilter-pymilter-1.0.5/Milter/policy.py", line 43, in __enter__
    self.acf = dbmopen(self.access_file,'r')
  File "/var/tmp/portage/dev-python/pymilter-1.0.5/work/pymilter-pymilter-1.0.5/Milter/policy.py", line 17, in dbmopen
    f.open(fname,mode)
  File "/var/tmp/portage/dev-python/pymilter-1.0.5/work/pymilter-pymilter-1.0.5/Milter/policy.py", line 8, in open
    self.f.open(fname,flags=flags)
bsddb3.db.DBNoSuchFileError: (2, 'No such file or directory')                                                           

That's because I had no makemap command available on the box where I run this test. I think

pymilter/testpolicy.py

Lines 19 to 21 in 7deec90

	cmd = 'tr : ! <test/access | makemap hash test/access.db'
	if os.system(cmd):
	print('failed!')

is invalid because it won't catch pipe errors.