azdev test doesn't work

When I run `azdev test`, I got the error as shown below:

> Traceback (most recent call last):
File "c:\users\zackl\azure-cli\venv\lib\site-packages\knack\cli.py", line 215, in invoke
cmd_result = self.invocation.execute(args)
File "c:\users\zackl\azure-cli\venv\lib\site-packages\knack\invocation.py", line 225, in execute
cmd_result = parsed_args.func(params)
File "c:\users\zackl\azure-cli\venv\lib\site-packages\knack\commands.py", line 148, in __call__
return self.handler(*args, **kwargs)
File "c:\users\zackl\azure-cli\venv\lib\site-packages\knack\commands.py", line 255, in _command_handler
result = op(client, **command_args) if client else op(**command_args)
File "c:\users\zackl\azure-cli\venv\lib\site-packages\azdev\operations\tests\__init__.py", line 48, in run_tests
test_index = _get_test_index(profile or current_profile(), discover)
File "c:\users\zackl\azure-cli\venv\lib\site-packages\azdev\operations\tests\__init__.py", line 332, in _get_test_index
test_index = _discover_tests(profile)
File "c:\users\zackl\azure-cli\venv\lib\site-packages\azdev\operations\tests\__init__.py", line 228, in _discover_tests
tests = _discover_module_tests(mod_name, mod_data)
File "c:\users\zackl\azure-cli\venv\lib\site-packages\azdev\operations\tests\__init__.py", line 160, in _discover_module_tests
contents = os.listdir(mod_data['filepath'])
FileNotFoundError: [WinError 3] 系统找不到指定的路径。: 'c:\\users\\zackl\\azure-cli\\src\\azure-cli\\azure\\cli\\tests'

The version of `azdev` is 0.1.18.

Inizia riproducendo `azdev test` con azdev 0.1.18 e leggi `azdev/operations/tests/__init__.py`, in particolare `_discover_module_tests` e `_get_test_index`. Traccia il motivo per cui la discovery raggiunge il percorso inesistente `src/azure-cli/azure/cli/tests`; il lavoro è completato quando la discovery dei test non solleva più `FileNotFoundError` e `azdev test` procede.

Scritto dal modello di indicizzazione a partire dal testo della issue.