Support finally in continue on 3.8+

Thanks to [bpo-32489](https://bugs.python.org/issue32489) and sadly
for rejection of my [PEP 601](https://www.python.org/dev/peps/pep-0601/)
finally in continue is supported in 3.8+. I checked the blame and looks
like there was already a commit for the same subject, but that only
changes the test and not actually changes the checker (dfe7fba08e)

parso/python/errors.py

@@ -449,7 +449,11 @@ class _ContinueChecks(SyntaxRule):
                 in_loop = True
             if block.type == 'try_stmt':
                 last_block = block.children[-3]
-                if last_block == 'finally' and leaf.start_pos > last_block.start_pos:
+                if (
+                    last_block == "finally"
+                    and leaf.start_pos > last_block.start_pos
+                    and self._normalizer.version < (3, 8)
+                ):
                     self.add_issue(leaf, message=self.message_in_finally)
                     return False  # Error already added
         if not in_loop:

test/test_python_errors.py

@@ -7,6 +7,8 @@ import warnings
 import pytest
 
 import parso
+
+from textwrap import dedent
 from parso._compatibility import is_pypy
 from .failing_examples import FAILING_EXAMPLES, indent, build_nested
 
@@ -324,3 +326,16 @@ def test_invalid_fstrings(code, message):
 def test_trailing_comma(code):
     errors = _get_error_list(code)
     assert not errors
+
+def test_continue_in_finally():
+    code = dedent('''\
+        for a in [1]:
+            try:
+                pass
+            finally:
+                continue
+        ''')
+    assert not _get_error_list(code, version="3.8")
+    assert _get_error_list(code, version="3.7")
+
+