Replace testr with pytest

Using a single test run orchestrator makes it easier to maintain
the project, especially as pytest is actively maintained.

Change-Id: I5c843984bc0a1b9264e744373e6a3fd9d43e99cd

test-requirements.txt

@@ -1,9 +1,4 @@
-coverage>=3.6
 fixtures>=3.0.0
-python-subunit
-testrepository>=0.0.17
-testscenarios>=0.4
-testtools>=0.9.36,!=1.2.0
 mock>=1.0
 # queries use pytest
 pytest

tox.ini

@@ -14,11 +14,11 @@ setenv =
    PYTHON_KEYRING_BACKEND=keyring.backends.null.Keyring
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-commands = python setup.py testr --slowest --testr-args='{posargs} tests.unit'
+commands = pytest elastic_recheck/tests/unit
 
 [testenv:functional]
 basepython = python3
-commands = python setup.py testr --slowest --testr-args='{posargs} tests.functional'
+commands = pytest  elastic_recheck/tests/functional
 
 [testenv:queries]
 basepython = python3
@@ -31,7 +31,10 @@ commands = {posargs}
 
 [testenv:cover]
 basepython = python3
-commands = python setup.py test --coverage --coverage-package-name='elastic_recheck' --testr-args='{posargs} tests.unit'
+deps =
+   {[testenv]deps}
+   pytest-cov
+commands = pytest --cov=elastic_recheck {posargs} elastic_recheck/tests/unit
 
 [testenv:run]
 basepython = python3