Fix tests

Add a RENormalizer so the easy_install.txt will be happy with scripts
generated on Python 2 (using open(..., 'U')) and on Python 3 (using just
open(...)).

This was suggested by @sallner.

(cherry picked from commit 2cf42066)

src/zc/buildout/testing.py

@@ -524,6 +524,9 @@ normalize_exception_type_for_python_2_and_3 = (
     re.compile(r'^(\w+\.)*([A-Z][A-Za-z0-9]+Error: )'),
     '\2')
 
+normalize_open_in_generated_script = (
+    re.compile(r"open\(__file__, 'U'\)"), 'open(__file__)')
+
 not_found = (re.compile(r'Not found: [^\n]+/(\w|\.)+/\r?\n'), '')
 
 # Setuptools now pulls in dependencies when installed.

src/zc/buildout/tests.py

@@ -3689,6 +3689,7 @@ def test_suite():
                 zc.buildout.testing.normalize_endings,
                 zc.buildout.testing.normalize_egg_py,
                 zc.buildout.testing.normalize_exception_type_for_python_2_and_3,
+                zc.buildout.testing.normalize_open_in_generated_script,
                 zc.buildout.testing.adding_find_link,
                 zc.buildout.testing.not_found,
                 normalize_bang,