Migrate from testr to stestr

* Replace .testr.conf by .stestr.conf for migration and update
  .gitignore and test-requirements.txt files accordingly
* Use py3 as the default runtime for tox and 3.18.0 as the
  minversion for tox
* Add a new job, openstack-cover-jobs, to run the coverage in Zuul
* Create cover environment in tox and make relevant changes
  in .gitignore

Signed-off-by: HeroicHitesh <email.hiteshkumar@gmail.com>
Change-Id: Ib4f5ffe86221b0c97c6839f6b69ddae17b2b47c1

.gitignore

@@ -1,15 +1,30 @@
 *.pyc
-*.swp
-*~
-build
-dist
+
+# Packages
+*.egg*
 *.egg-info
-.venv
-AUTHORS
-ChangeLog
+dist
+build
+
+# Unit test / coverage reports
+cover/
+.coverage*
+!.coveragerc
 .tox
-.coverage
-cover
-.testrepository
+.stestr/
+.venv
+
+# Mr Developer
 .project
 .pydevproject
+
+# pbr generates these
+AUTHORS
+ChangeLog
+
+# Editors
+*.swp
+*~
+
+# Files created by releasenotes build
+releasenotes/build

.stestr.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+test_path=./heat_cfnclient/tests/
+top_dir=./

.testr.conf

@@ -1,4 +0,0 @@
-[DEFAULT]
-test_command=${PYTHON:-python} -m subunit.run discover -t ./ . $LISTOPT $IDOPTION
-test_id_option=--load-list $IDFILE
-test_list_option=--list

.zuul.yaml

@@ -1,3 +1,4 @@
 - project:
     templates:
       - openstack-python3-xena-jobs
+      - openstack-cover-jobs

test-requirements.txt

@@ -6,5 +6,5 @@
 hacking>=3.0.1,<3.1.0 # Apache-2.0
 coverage>=3.6
 discover
-testrepository>=0.0.18
+stestr>=2.0.0 # Apache-2.0
 testtools>=0.9.36,!=1.2.0

tox.ini

@@ -1,7 +1,7 @@
 [tox]
-envlist = py38,pep8
+envlist = py3,pep8
 ignore_basepython_conflict = true
-minversion = 3.1.0
+minversion = 3.18.0
 skipsdist = True
 
 [testenv]
@@ -13,8 +13,7 @@ setenv = VIRTUAL_ENV={envdir}
 usedevelop = True
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-commands =
-  python setup.py testr --slowest --testr-args='{posargs}'
+commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
 commands = flake8 heat_cfnclient bin/heat-cfn bin/heat-watch
@@ -23,8 +22,19 @@ commands = flake8 heat_cfnclient bin/heat-cfn bin/heat-watch
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
+allowlist_externals = find
+setenv =
+  {[testenv]setenv}
+  PYTHON=coverage run --source heat_cfnclient --parallel-mode
 commands =
-  python setup.py testr --coverage
+  coverage erase
+  find . -type f -name "*.pyc" -delete
+  stestr run {posargs}
+  coverage combine
+  coverage html -d cover
+  coverage xml -o cover/coverage.xml
+  coverage report
 
 [flake8]
 # F841 local variable 'json_template' is assigned to but never used