test for original "v0" index XML compatibility

The original index.xml format needs to stay around for backwards
compatibility, but we shouldn't touch it anymore once the new format is in
place.  This is a test to make sure `fdroid update` can still generate the
correct XML.

install_list and uninstall_list should be tuples or lists in order to
ensure that the order is preserved.

These tests also check that the added and lastupdated dates are
working correct, based on the dates in tests/stats/known_apks.txt. I
could see no useful way to test the timestamp, it is just hardcoded
using a regexp search-and-replace.  Running these tests manually might
require deleting tmp/apkcache.

tests/config.py

@@ -0,0 +1,35 @@
+
+repo_url = "https://MyFirstFDroidRepo.org/fdroid/repo"
+repo_name = "My First F-Droid Repo Demo"
+repo_icon = "fdroid-icon.png"
+repo_description = """
+This is a repository of apps to be used with F-Droid. Applications in this
+repository are either official binaries built by the original application
+developers, or are binaries built from source by the admin of f-droid.org
+using the tools on https://gitlab.com/u/fdroid.
+"""
+
+archive_older = 3
+archive_url = "https://f-droid.org/archive"
+archive_name = "My First F-Droid Archive Demo"
+archive_icon = "fdroid-icon.png"
+archive_description = """
+The repository of older versions of applications from the main demo repository.
+"""
+
+repo_keyalias = "sova"
+keystore = "keystore.jks"
+keystorepass = "r9aquRHYoI8+dYz6jKrLntQ5/NJNASFBacJh7Jv2BlI="
+keypass = "r9aquRHYoI8+dYz6jKrLntQ5/NJNASFBacJh7Jv2BlI="
+keydname = "CN=sova, OU=F-Droid"
+
+mirrors = (
+    'https://foo.bar/fdroid',
+    'http://foobarfoobarfoobar.onion/fdroid',
+)
+
+update_stats = True
+accepted_formats = ('json', 'txt', 'yml')
+
+install_list = 'org.adaway'
+uninstall_list = ('com.android.vending', 'com.facebook.orca', )