Switch to stestr

According to Openstack summit session [1],
stestr is maintained project to which all Openstack projects should migrate.
Let's switch to stestr as other projects have already moved to it.

[1] https://etherpad.openstack.org/p/YVR-python-pti

Change-Id: I5e57994077795bcc25861a081ef114fa97e01bef

.gitignore

@@ -16,5 +16,5 @@ doc/build
 searchlightclient/versioninfo
 *.egg-info
 *.log
-.testrepository
+.stestr/
 *.swp

.stestr.conf

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

.testr.conf

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

test-requirements.txt

@@ -7,5 +7,5 @@ hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
 mock>=2.0.0 # BSD
-testrepository>=0.0.18 # Apache-2.0/BSD
+stestr>=2.0.0 # Apache-2.0
 testtools>=2.2.0 # MIT

tox.ini

@@ -12,7 +12,7 @@ deps =
        -r{toxinidir}/test-requirements.txt
 commands =
     find . -type f -name "*.pyc" -delete
-    python setup.py testr --slowest --testr-args='{posargs}'
+    stestr run --slowest {posargs}
 whitelist_externals = find
 
 [testenv:pypy]
@@ -39,7 +39,13 @@ passenv = OS_*
 
 [testenv:cover]
 basepython = python3
-commands = python setup.py testr --coverage --testr-args='{posargs}'
+setenv =
+    PYTHON=coverage run --source $project --parallel-mode
+commands =
+    stestr run '{posargs}'
+    coverage combine
+    coverage html -d cover
+    coverage xml -o cover/coverage.xml
 
 [testenv:docs]
 basepython = python3