Convert tox to run the coverage command, like travis.

Fixes #87

src/zope/interface/tests/test_adapter.py

@@ -1390,7 +1390,7 @@ def test__normalize_name_str(self):
         STR = b'str'
         if sys.version_info[0] < 3:
             self.assertEqual(_normalize_name(STR), unicode(STR))
-        else:
+        else: # pragma: no cover (tox runs coverage on Python 2)
             self.assertEqual(_normalize_name(STR), str(STR, 'ascii'))
 
     def test__normalize_name_unicode(self):

src/zope/interface/tests/test_advice.py

@@ -221,7 +221,7 @@ class Meta(type):
         self.assertEqual(self._callFUT((Meta, type)), Metameta)
 
     @_skip_under_py2
-    def test_meta_of_class_py3k(self):
+    def test_meta_of_class_py3k(self): # pragma: no cover (tox runs coverage on Python 2)
         # Work around SyntaxError under Python2.
         EXEC = '\n'.join([
         'class Metameta(type):',
@@ -249,7 +249,7 @@ class B(type):
         self.assertEqual(self._callFUT((A, B,)), Meta_B)
 
     @_skip_under_py2
-    def test_multiple_in_hierarchy_py3k(self):
+    def test_multiple_in_hierarchy_py3k(self): # pragma: no cover (tox runs coverage on Python 2)
         # Work around SyntaxError under Python2.
         EXEC = '\n'.join([
         'class Meta_A(type):',
@@ -282,7 +282,7 @@ class B(type):
         self.assertRaises(TypeError, self._callFUT, (A, B,))
 
     @_skip_under_py2
-    def test_multiple_not_in_hierarchy_py3k(self):
+    def test_multiple_not_in_hierarchy_py3k(self): # pragma: no cover (tox runs coverage on Python 2)
         # Work around SyntaxError under Python2.
         EXEC = '\n'.join([
         'class Meta_A(type):',

src/zope/interface/tests/test_declarations.py

@@ -31,7 +31,7 @@ def _run_generated_code(self, code, globs, locs,
                 exec(code, globs, locs)
                 self.assertEqual(len(log), 0) # no longer warn
                 return True
-            else:
+            else: # pragma: no cover (tox runs coverage on Python 2)
                 try:
                     exec(code, globs, locs)
                 except TypeError:
@@ -752,7 +752,7 @@ def test_simple(self):
             warnings.resetwarnings()
             try:
                 exec(CODE, globs, locs)
-            except TypeError:
+            except TypeError: # pragma: no cover (tox runs coverage on Python 2)
                 if not PYTHON3:
                     raise
             else:

tox.ini

@@ -28,12 +28,11 @@ usedevelop = true
 basepython =
     python2.7
 commands =
-    nosetests --with-xunit --with-xcoverage {posargs}
+    coverage run setup.py -q test -q {posargs}
+    coverage report --skip-covered
 deps =
     {[testenv]deps}
-    nose
     coverage
-    nosexcover
 
 [testenv:docs]
 basepython =