[PATCH 5 of 7 hglib] tests: write out bytes instead of strings to test files (issue4520)

[Brett Cannon]

# HG changeset patch
# User Brett Cannon <brett at python.org>
# Date 1427329421 14400
#      Wed Mar 25 20:23:41 2015 -0400
# Node ID c65b266b8abb6d442740508c08c29dfe8c712ffa
# Parent  5efe91a4c2d49d74d1104edd50cd5a82003df4b6
tests: write out bytes instead of strings to test files (issue4520)

diff -r 5efe91a4c2d4 -r c65b266b8abb tests/common.py
--- a/tests/common.py	Wed Mar 25 20:21:57 2015 -0400
+++ b/tests/common.py	Wed Mar 25 20:23:41 2015 -0400
@@ -45,5 +45,5 @@
     def append(self, path, *args):
         f = open(path, 'ab')
         for a in args:
-            f.write(str(a))
+            f.write(a.encode('latin-1'))
         f.close()