Moved sshuttle/tests into tests to.

Having the tests in a `tests` directory in root is the most common
approach. Also moved pytest's conftest.py into `tests` making the
fixture available for client and server tests.

tests/client/test_sdnotify.py

@@ -0,0 +1,64 @@
+from mock import Mock, patch, call
+import socket
+
+import sshuttle.sdnotify
+
+
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_invalid_socket_path(mock_get):
+    mock_get.return_value = 'invalid_path'
+    assert not sshuttle.sdnotify.send(sshuttle.sdnotify.ready())
+
+
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_socket_not_there(mock_get):
+    mock_get.return_value = '/run/valid_nonexistent_path'
+    assert not sshuttle.sdnotify.send(sshuttle.sdnotify.ready())
+
+
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_no_message(mock_get):
+    mock_get.return_value = '/run/valid_path'
+    assert not sshuttle.sdnotify.send()
+
+
+@patch('sshuttle.sdnotify.socket.socket')
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_socket_error(mock_get, mock_socket):
+    mock_get.return_value = '/run/valid_path'
+    mock_socket.side_effect = socket.error('test error')
+    assert not sshuttle.sdnotify.send(sshuttle.sdnotify.ready())
+
+
+@patch('sshuttle.sdnotify.socket.socket')
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_sendto_error(mock_get, mock_socket):
+    message = sshuttle.sdnotify.ready()
+    socket_path = '/run/valid_path'
+
+    sock = Mock()
+    sock.sendto.side_effect = socket.error('test error')
+    mock_get.return_value = '/run/valid_path'
+    mock_socket.return_value = sock
+
+    assert not sshuttle.sdnotify.send(message)
+    assert sock.sendto.mock_calls == [
+        call(message, socket_path),
+    ]
+
+
+@patch('sshuttle.sdnotify.socket.socket')
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify(mock_get, mock_socket):
+    messages = [sshuttle.sdnotify.ready(), sshuttle.sdnotify.status('Running')]
+    socket_path = '/run/valid_path'
+
+    sock = Mock()
+    sock.sendto.return_value = 1
+    mock_get.return_value = '/run/valid_path'
+    mock_socket.return_value = sock
+
+    assert sshuttle.sdnotify.send(*messages)
+    assert sock.sendto.mock_calls == [
+        call(b'\n'.join(messages), socket_path),
+    ]