resolve another use of commands module for python3 compat

03255001d6 moved commands module to src/tito/compat.py to handle
differences between python2 and python3, but missed a bit that
did not show up in unit or functional tests.

Fix those occurences and add unit test to detect the regression.

src/tito/builder/main.py

@@ -144,7 +144,7 @@ class BuilderBase(object):
         """
         if not self.no_cleanup:
             debug("Cleaning up [%s]" % self.rpmbuild_dir)
-            commands.getoutput("rm -rf %s" % self.rpmbuild_dir)
+            getoutput("rm -rf %s" % self.rpmbuild_dir)
         else:
             print("WARNING: Leaving rpmbuild files in: %s" % self.rpmbuild_dir)
 
@@ -165,7 +165,7 @@ class BuilderBase(object):
         """
         Create the build directories. Can safely be called multiple times.
         """
-        commands.getoutput("mkdir -p %s %s %s %s" % (
+        getoutput("mkdir -p %s %s %s %s" % (
             self.rpmbuild_basedir, self.rpmbuild_dir,
             self.rpmbuild_sourcedir, self.rpmbuild_builddir))
         self._check_build_dirs_access()

src/tito/compat.py

@@ -43,7 +43,4 @@ def getoutput(cmd):
     Returns output of executing cmd in a shell.
     Supports Python 2.4 and 3.x.
     """
-    if PY2:
-        return commands.getoutput(cmd)
-    else:
-        return subprocess.getoutput(cmd)
+    return getstatusoutput(cmd)[1]

test/unit/pep8-tests.py

@@ -90,6 +90,11 @@ class UglyHackishTest(TitoUnitTestFixture):
         result = int(getoutput(cmd))
         self.assertEqual(result, 0, "Found commands module (not supported in Python 3)")
 
+    def test_use_commands(self):
+        cmd = "find . -type f -regex '.*\.py$' -exec egrep 'commands\.' {} + | grep -v 'compat\.py' | wc -l"
+        result = int(getoutput(cmd))
+        self.assertEqual(result, 0, "Found commands module (not supported in Python 3)")
+
     def test_print_function(self):
         cmd = "find . -type f -regex '.*\.py$' -exec grep '^[[:space:]]*print .*' {} + | wc -l"
         result = int(getoutput(cmd))