Pytest failures due to duplicated test file names

[busunkim96]

I generated text-to-speech, which has two versions (v1 and v1beta1). The tests directory looks like this:

tests
└── unit
    ├── texttospeech_v1
    │   └── test_text_to_speech.py
    └── texttospeech_v1beta1
        └── test_text_to_speech.py

The tests run fine with the noxfile provided by the generator --cov={{ api.naming.module_namespace|join("/") }}/{{ api.naming.versioned_module_name }}/, but fail with a less specific invocation like --cov=tests.unit.

___________ ERROR collecting tests/unit/texttospeech_v1beta1/test_text_to_speech.py ____________
import file mismatch:
imported module 'test_text_to_speech' has this __file__ attribute:
  /usr/local/google/home/busunkim/github/google-cloud-python/texttospeech/tests/unit/texttospeech_v1/test_text_to_speech.py
which is not the same as the test file we want to collect:
  /usr/local/google/home/busunkim/github/google-cloud-python/texttospeech/tests/unit/texttospeech_v1beta1/test_text_to_speech.py
HINT: remove __pycache__ / .pyc files and/or use a unique basename for your test file modules

According to pytest-dev/pytest#3151, every test file name should be distinct name or there should be __init__.py files. The monolith seems to go the route of having distinct names for every file.

tests
├── system
│   └── gapic
│       ├── v1
│       │   └── test_system_speech_v1.py
│       └── v1p1beta1
│           └── test_system_speech_v1p1beta1.py
└── unit
    ├── gapic
    │   ├── v1
    │   │   └── test_speech_client_v1.py
    │   └── v1p1beta1
    │       └── test_speech_client_v1p1beta1.py
    └── test_helpers.py

[software-dov]

Leaning towards having an __init__.py file unless you feel strongly otherwise.
Mild soapbox: names should be short and pithy, paths should be detailed and descriptive.

[busunkim96]

@software-dov That sounds good to me.

[busunkim96]

Closed by #270