Add check for deprecated method assertEquals

The proper one is assertEqual, assertEquals is deprecated as of 2.7.
Of course, remembering which one is good and which one is bad is
absolutely impossible.

Change-Id: I79c5417ea2d11091ed7d73cf28c534feef6f7ba9

hacking/core.py

@@ -639,6 +639,22 @@ def hacking_no_cr(physical_line):
         return (pos, "H601: Windows style line endings not allowed in code")
 
 
+@flake8ext
+def hacking_no_assert_equals(logical_line, tokens):
+    r"""assertEquals() is deprecated, use assertEqual instead.
+
+    Okay: self.assertEqual(0, 0)
+    H602: self.assertEquals(0, 0)
+    """
+
+    for token_type, text, start_index, _, _ in tokens:
+
+        if token_type == tokenize.NAME and text == "assertEquals":
+            yield (
+                start_index[1],
+                "H602: assertEquals is deprecated, use assertEqual")
+
+
 FORMAT_RE = re.compile("%(?:"
                        "%|"           # Ignore plain percents
                        "(\(\w+\))?"   # mapping key

setup.cfg

@@ -39,6 +39,7 @@ flake8.extension =
     H404 = hacking.core:hacking_docstring_multiline_start
     H501 = hacking.core:hacking_no_locals
     H601 = hacking.core:hacking_no_cr
+    H602 = hacking.core:hacking_no_assert_equals
     H700 = hacking.core:hacking_localization_strings
     H801 = hacking.core:OnceGitCheckCommitTitleBug
     H802 = hacking.core:OnceGitCheckCommitTitleLength