Fix bindep testing with distro 1.7.0 and greater

The 1.7.0 release of distro moves the source code around [0] which
requires us to update our monkey patching of distro to make tests work.
Because distro 1.7.0 does not support python < 3.6 we update bindep's
testing to accomodate both old and new distro to enable python 2.7 and
3.5 testing.

[0] 4d76bd160f

Change-Id: I6cc3bedaa9753dc86d6560d32961b5a22cf3a36e

bindep/tests/test_depends.py

@@ -54,12 +54,18 @@ class DistroFixture(fixtures.Fixture):
         self.distro_name = distro_name.lower()
 
     def _setUp(self):
+        # Python 2.7 and 3.5 need older distro which has different src paths
+        if distro.__version__ < '1.7.0':
+            distro_patch_path = 'distro._distro'
+        else:
+            distro_patch_path = 'distro.distro._distro'
         # This type of monkey patching is borrowed from the distro test
         # suite.
         os_release = os.path.join(FIXTURE_DIR, self.distro_name,
                                   'etc', 'os-release')
         mydistro = distro.LinuxDistribution(False, os_release, 'non')
-        self.useFixture(fixtures.MonkeyPatch('distro._distro', mydistro))
+        self.useFixture(
+            fixtures.MonkeyPatch(distro_patch_path, mydistro))
         if self.distro_name not in ['darwin']:
             self.useFixture(fixtures.MonkeyPatch(
                 'platform.system', lambda *x: 'Linux'))

requirements.txt

@@ -1,4 +1,5 @@
-distro
+distro<1.7.0 ; python_version < '3.6'
+distro>=1.7.0 ; python_version >= '3.6'
 pbr>=2.0.0  # Apache-2.0
 Parsley
 packaging ; python_version >= '3.6'