Switch to asynctest for Py 3.7 support.

Decided to switch the tests to using asynctest so that we can guarantee
support on Python 3.7 and newer.  Also added pins in setup.cfg and a
tox.ini file if you want to use it.

setup.cfg

@@ -29,17 +29,17 @@ classifiers =
 [options]
 packages = find:
 install_requires =
-    tornado
+    tornado>=5
 
 [options.extras_require]
 dev =
-    coverage
-    flake8
-    flake8-import-order
-    sphinx
-    sphinx-autodoc-typehints
-    tox
-    yapf
+    asynctest==0.13.0
+    coverage==5.5
+    flake8==3.8.4
+    flake8-import-order==0.18.1
+    sphinx==3.5.2
+    sphinx-autodoc-typehints==1.11.1
+    yapf==0.30.0
 
 [options.packages.find]
 exclude =

tests/test_processor.py

@@ -1,15 +1,21 @@
 import asyncio
 import time
-import unittest
+
+import asynctest
 
 from sprockets_statsd import statsd
 from tests import helpers
 
 
-class ProcessorTestCase(unittest.IsolatedAsyncioTestCase):
-    def setUp(self):
-        super().setUp()
+class ProcessorTestCase(asynctest.TestCase):
+    async def setUp(self):
         self.test_timeout = 5.0
+        super().setUp()
+        await self.asyncSetUp()
+
+    async def tearDown(self):
+        await self.asyncTearDown()
+        super().tearDown()
 
     async def wait_for(self, fut):
         try:
@@ -18,7 +24,6 @@ class ProcessorTestCase(unittest.IsolatedAsyncioTestCase):
             self.fail('future took too long to resolve')
 
     async def asyncSetUp(self):
-        await super().asyncSetUp()
         self.statsd_server = helpers.StatsdServer()
         self.statsd_task = asyncio.create_task(self.statsd_server.run())
         await self.statsd_server.wait_running()
@@ -26,7 +31,6 @@ class ProcessorTestCase(unittest.IsolatedAsyncioTestCase):
     async def asyncTearDown(self):
         self.statsd_task.cancel()
         await self.statsd_server.wait_closed()
-        await super().asyncTearDown()
 
 
 class ProcessorTests(ProcessorTestCase):

tox.ini

@@ -0,0 +1,19 @@
+[tox]
+envlist = lint,py37,py39,tornado5
+toxworkdir = ./build/tox
+
+[testenv]
+deps =
+	.[dev]
+commands =
+	python -m unittest
+
+[testenv:lint]
+commands =
+	flake8 sprockets_statsd tests
+	yapf -dr sprockets_statsd tests
+
+[testenv:tornado5]
+deps =
+	tornado>=5,<6
+	.[dev]