Applying black formatting

- Fixing flake8 configuration to agree with black
- Adding black validation check to github actions

test/test_threads.py

@@ -1,6 +1,6 @@
-'''
+"""
 thread test
-'''
+"""
 
 import platform
 import socket
@@ -16,13 +16,13 @@ import test_capability_capnp
 
 
 @pytest.mark.skipif(
-    platform.python_implementation() == 'PyPy',
-    reason="pycapnp's GIL handling isn't working properly at the moment for PyPy"
+    platform.python_implementation() == "PyPy",
+    reason="pycapnp's GIL handling isn't working properly at the moment for PyPy",
 )
 def test_making_event_loop():
-    '''
+    """
     Event loop test
-    '''
+    """
     capnp.remove_event_loop(True)
     capnp.create_event_loop()
 
@@ -31,13 +31,13 @@ def test_making_event_loop():
 
 
 @pytest.mark.skipif(
-    platform.python_implementation() == 'PyPy',
-    reason="pycapnp's GIL handling isn't working properly at the moment for PyPy"
+    platform.python_implementation() == "PyPy",
+    reason="pycapnp's GIL handling isn't working properly at the moment for PyPy",
 )
 def test_making_threaded_event_loop():
-    '''
+    """
     Threaded event loop test
-    '''
+    """
     # The following raises a KjException, and if not caught causes an SIGABRT:
     # kj/async.c++:973: failed: expected head == nullptr; EventLoop destroyed with events still in the queue.
     # Memory leak?; head->trace() = kj::_::ForkHub<kj::_::Void>
@@ -54,27 +54,28 @@ def test_making_threaded_event_loop():
 
 
 class Server(test_capability_capnp.TestInterface.Server):
-    '''
+    """
     Server
-    '''
+    """
+
     def __init__(self, val=100):
         self.val = val
 
     def foo(self, i, j, **kwargs):
-        '''
+        """
         foo
-        '''
+        """
         return str(i * 5 + self.val)
 
 
 @pytest.mark.skipif(
-    platform.python_implementation() == 'PyPy',
-    reason="pycapnp's GIL handling isn't working properly at the moment for PyPy"
+    platform.python_implementation() == "PyPy",
+    reason="pycapnp's GIL handling isn't working properly at the moment for PyPy",
 )
 def test_using_threads():
-    '''
+    """
     Thread test
-    '''
+    """
     capnp.remove_event_loop(True)
     capnp.create_event_loop(True)
 
@@ -94,4 +95,4 @@ def test_using_threads():
     remote = cap.foo(i=5)
     response = remote.wait()
 
-    assert response.x == '125'
+    assert response.x == "125"