Revert "Set type of keyword arguments to Dict[unicode, Any] in Python 2. (#1971)"

This reverts commit 51fa569.

Sadly this breaks some of our code. :-(

Author: Guido van Rossum

mypy/checker.py

@@ -554,9 +554,8 @@ def is_implicit_any(t: Type) -> bool:
                                                            [arg_type])
                     elif typ.arg_kinds[i] == nodes.ARG_STAR2:
                         arg_type = self.named_generic_type('builtins.dict',
-                                                           [self.unicode_type(),
+                                                           [self.str_type(),
                                                             arg_type])
-
                     item.arguments[i].variable.type = arg_type
 
                 # Type check initialization expressions.
@@ -2116,13 +2115,6 @@ def str_type(self) -> Instance:
         """Return instance type 'str'."""
         return self.named_type('builtins.str')
 
-    def unicode_type(self) -> Instance:
-        """Return instance type 'unicode'."""
-        if self.options.python_version[0] >= 3:
-            return self.named_type('builtins.str')
-        else:
-            return self.named_type('builtins.unicode')
-
     def check_type_equivalency(self, t1: Type, t2: Type, node: Context,
                                msg: str = messages.INCOMPATIBLE_TYPES) -> None:
         """Generate an error if the types are not equivalent. The

test-data/unit/python2eval.test

@@ -128,25 +128,6 @@ print '>', ['a', b'b', u'c']
 [out]
 > [u'a', 'b', u'c']
 
-[case testUnicodeLiteralsReadKwargs_python2]
-from __future__ import unicode_literals
-def f(**kwargs):  # type: (...) -> None
-  return kwargs.get('a', '')
-f(a='b')
-[out]
-
-[case testUnicodeStrReadKwargs_python2]
-def f(**kwargs):  # type: (...) -> None
-  return kwargs.get(u'a', '')
-f(a='b')
-[out]
-
-[case testPy2StrReadKwargs_python2]
-def f(**kwargs):  # type: (...) -> None
-  return kwargs.get('a', '')
-f(a='b')
-[out]
-
 [case testUnicodeLiteralsKwargs_python2]
 from __future__ import unicode_literals
 def f(**kwargs):  # type: (...) -> None