Test failure: test_platform

```
# python3.6 -m test test_platform -v
== CPython 3.6.0 (default, Dec 29 2016, 04:29:02) [GCC 6.2.1 20161215]
== Linux-4.4.0-57-generic-x86_64-with-Ubuntu-17.04-zesty little-endian
== hash algorithm: siphash24 64bit
== cwd: /tmp/test_python_410
== encodings: locale=ANSI_X3.4-1968, FS=ascii
Testing with flags: sys.flags(debug=0, inspect=0, interactive=0, optimize=0, dont_write_bytecode=0, no_user_site=0, no_site=0, ignore_environment=0, verbose=0, bytes_warning=0, quiet=0, hash_randomization=1, isolated=0)
Run tests sequentially
0:00:00 [1/1] test_platform
test_dist_deprecation (test.test_platform.DeprecationTest) ... ok
test_linux_distribution_deprecation (test.test_platform.DeprecationTest) ... ok
test_architecture (test.test_platform.PlatformTest) ... ok
test_architecture_via_symlink (test.test_platform.PlatformTest) ... ok
test_dist (test.test_platform.PlatformTest) ... ok
test_java_ver (test.test_platform.PlatformTest) ... ok
test_libc_ver (test.test_platform.PlatformTest) ... ok
test_linux_distribution_encoding (test.test_platform.PlatformTest) ... FAIL
test_mac_ver (test.test_platform.PlatformTest) ... ok
test_mac_ver_with_fork (test.test_platform.PlatformTest) ... skipped 'OSX only test'
test_machine (test.test_platform.PlatformTest) ... ok
test_node (test.test_platform.PlatformTest) ... ok
test_parse_release_file (test.test_platform.PlatformTest) ... ok
test_platform (test.test_platform.PlatformTest) ... ok
test_popen (test.test_platform.PlatformTest) ... ok
test_processor (test.test_platform.PlatformTest) ... ok
test_release (test.test_platform.PlatformTest) ... ok
test_sys_version (test.test_platform.PlatformTest) ... ok
test_system (test.test_platform.PlatformTest) ... ok
test_system_alias (test.test_platform.PlatformTest) ... ok
test_uname (test.test_platform.PlatformTest) ... ok
test_uname_win32_ARCHITEW6432 (test.test_platform.PlatformTest) ... skipped 'windows only test'
test_version (test.test_platform.PlatformTest) ... ok
test_win32_ver (test.test_platform.PlatformTest) ... ok

======================================================================
FAIL: test_linux_distribution_encoding (test.test_platform.PlatformTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3.6/test/test_platform.py", line 348, in test_linux_distribution_encoding
    self.assertEqual(distname, 'Fedora')
AssertionError: 'Ubuntu' != 'Fedora'
- Ubuntu
+ Fedora

----------------------------------------------------------------------
Ran 24 tests in 0.724s

FAILED (failures=1, skipped=2)
test test_platform failed
test_platform failed

1 test failed:
    test_platform

Total duration: 860 ms
Tests result: FAILURE

```

This test can be "fixed" by modifying the platform-lsbrelease.diff patch in the following way:

```diff
diff --git a/debian/patches/platform-lsbrelease.diff b/debian/patches/platform-lsbrelease.diff
index 5b9b5a8..fe66d9a 100644
--- a/debian/patches/platform-lsbrelease.diff
+++ b/debian/patches/platform-lsbrelease.diff
@@ -31,7 +31,7 @@ Index: b/Lib/platform.py
 + # check for the Debian/Ubuntu /etc/lsb-release file first, needed so
 + # that the distribution doesn't get identified as Debian.
 + try:
-+ with open("/etc/lsb-release", "r") as etclsbrel:
++ with open(os.path.join(_UNIXCONFDIR, "lsb-release"), "r") as etclsbrel:
 + for line in etclsbrel:
 + m = _distributor_id_file_re.search(line)
 + if m:
```

Other information:

I'm using the ubuntu:zesty docker image:

```
# lsb_release -rd
Description: Ubuntu Zesty Zapus (development branch)
Release: 17.04
# apt-cache policy python3.6
python3.6:
  Installed: 3.6.0-1
  Candidate: 3.6.0-1
  Version table:
 *** 3.6.0-1 500
        500 http://archive.ubuntu.com/ubuntu zesty/universe amd64 Packages
        100 /var/lib/dpkg/status
```