test_landings: increase git landing coverage (bug 1934485) (#190)

* upgrade landings tests to work with both Hg and Git repos
* fix a few simple bugs in the Git implementation

---------

test_landings: update repo_mc factory to allow parameters
GitSCM.update_repo: use git fetch rather than pull
GitSCM: set Git user on local clone
test: ignore denyCurrentBranch in git repo fixture
test_landings: allow create_patch_revision to fetch normal patches by index
*SCM.apply_patch: add suffix to temporary files
tests: don't rstrip diff fixtures (git requires a trailing newline)
test_git: initialise test_repo with seed patch
tests: add git_repo to landings tests
test_landings: add repo_mc parametrable factory
test-landings: add hg_repo_mc fixture
conftest: dos2unix conversion

Co-authored-by: Connor Sheehan <[email protected]>

src/lando/api/tests/conftest.py

@@ -30,8 +30,13 @@
 from lando.main.models import SCM_LEVEL_1, SCM_LEVEL_3, Profile, Repo
 from lando.main.scm import SCM_TYPE_HG
 from lando.main.support import LegacyAPIException
+from lando.main.tests.conftest import git_repo, git_repo_seed
 from lando.utils.phabricator import PhabricatorClient
 
+# We need some local usage of those imported fixtures to satisfy the linters.
+# This is it.
+__all__ = ["git_repo", "git_repo_seed"]
+
 PATCH_NORMAL_1 = r"""
 # HG changeset patch
 # User Test User <[email protected]>
@@ -45,7 +50,7 @@
 @@ -1,1 +1,2 @@
  TEST
 +adding another line
-""".strip()
+""".lstrip()
 
 PATCH_NORMAL_2 = r"""
 # HG changeset patch
@@ -61,7 +66,7 @@
  TEST
  adding another line
 +adding one more line
-""".strip()
+""".lstrip()
 
 PATCH_NORMAL_3 = r"""
 # HG changeset patch
@@ -82,7 +87,7 @@
 +++ b/blah.txt
 @@ -0,0 +1,1 @@
 +TEST
-""".strip()
+""".lstrip()
 
 
 @pytest.fixture