[PATCH v2] tests: fix assertion rewriting in some tests with pytest-3.0.0+

[Thomas De Schampheleire]

# HG changeset patch
# User Thomas De Schampheleire <thomas.de.schampheleire at gmail.com>
# Date 1473428048 -7200
#      Fri Sep 09 15:34:08 2016 +0200
# Node ID 728f0df729b15b40165c1f8bfc26f45b25ccd5d3
# Parent  59639343672495cb89be54b98f1d6d3a4c44307c
tests: fix assertion rewriting in some tests with pytest-3.0.0+

Since pytest 3.0.0, asserts present in modules that are not directly seen by
pytest as 'test modules', are no longer rewritten to have improved
reporting, unless they are explicitly marked as up-for-rewriting.
Rationale from pytest upstream:

    However since we do not want to test different bytecode then you will
    run in production this hook only re-writes test modules themselves as
    well as any modules which are part of plugins. Any other imported module
    will not be re-written and normal assertion behaviour will happen.

This is e.g. the case for asserts in files like
kallithea/tests/api/api_base.py and kallithea/tests/models/common.py.

See
http://doc.pytest.org/en/latest/changelog.html#id13
http://doc.pytest.org/en/latest/writing_plugins.html#assertion-rewriting

diff --git a/kallithea/__init__.py b/kallithea/__init__.py
--- a/kallithea/__init__.py
+++ b/kallithea/__init__.py
@@ -86,3 +86,8 @@ if len(VERSION) > 3:
 import uuid
 if not hasattr(uuid, '_uuid_generate_random'):
     uuid._uuid_generate_random = None
+
+# make sure that all asserts under kallithea/tests benefit from advanced assert
+# reporting, before importing these modules.
+import pytest
+pytest.register_assert_rewrite('kallithea.tests')