couldn't find requirements.txt

```
$ pyp2rpm google-assistant-sdk -s -d ~/tmp/gas -b 3 -v ''
INFO Pyp2rpm initialized.
INFO Using /home/brian/tmp/gas as directory to save source.
INFO Downloaded package from PyPI: /home/brian/tmp/gas/google-assistant-sdk-0.3.3.tar.gz.
INFO Getting metadata from setup.py using SetupPyMetadataExtractor.
INFO Running extract_dist command using current interpreter.
ERROR Subprocess failed, stdout: , stderr: Traceback (most recent call last):
File "setup.py", line 55, in
'samples': list(samples_requirements()),
File "setup.py", line 32, in samples_requirements
'requirements.txt')) as f:
FileNotFoundError: [Errno 2] No such file or directory: 'googlesamples/assistant/grpc/requirements.txt'

ERROR Error occured, trying alternative python interpreter.
ERROR Subprocess failed, stdout: , stderr: Traceback (most recent call last):
File "setup.py", line 55, in
'samples': list(samples_requirements()),
File "setup.py", line 32, in samples_requirements
'requirements.txt')) as f:
IOError: [Errno 2] No such file or directory: 'googlesamples/assistant/grpc/requirements.txt'

Failed to extract data from setup.py script.
```
The contents of the tarball fetched from pypi:

```
$ tar tzvf ~/tmp/gas/google-assistant-sdk-0.3.3.tar.gz | grep setup-rw-r--r-- fleker/_guest 93 2017-07-19 20:51 google-assistant-sdk-0.3.3/setup.cfg
-rw-r--r-- fleker/_guest 2769 2017-07-19 20:29 google-assistant-sdk-0.3.3/setup.py
[brian@pc ~]$ tar tzvf ~/tmp/gas/google-assistant-sdk-0.3.3.tar.gz
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/
-rw-r--r-- fleker/_guest 1410 2017-07-19 20:49 google-assistant-sdk-0.3.3/CHANGELOG.rst
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/
-rw-r--r-- fleker/_guest 1 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/dependency_links.txt
-rw-r--r-- fleker/_guest 284 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/entry_points.txt
-rw-r--r-- fleker/_guest 38 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/namespace_packages.txt
-rw-r--r-- fleker/_guest 6340 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/PKG-INFO
-rw-r--r-- fleker/_guest 172 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/requires.txt
-rw-r--r-- fleker/_guest 768 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/SOURCES.txt
-rw-r--r-- fleker/_guest 14 2017-07-19 20:51 google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/top_level.txt
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/googlesamples/
-rw-r--r-- fleker/_guest 786 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/__init__.py
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/googlesamples/assistant/
-rw-r--r-- fleker/_guest 796 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/assistant/__init__.py
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/googlesamples/assistant/grpc/
-rw-r--r-- fleker/_guest 625 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/assistant/grpc/__init__.py
-rw-r--r-- fleker/_guest 2335 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/assistant/grpc/assistant_helpers.py
-rw-r--r-- fleker/_guest 13017 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/assistant/grpc/audio_helpers.py
-rw-r--r-- fleker/_guest 13515 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/assistant/grpc/pushtotalk.py
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/googlesamples/assistant/library/
-rw-r--r-- fleker/_guest 0 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/assistant/library/__init__.py
-rw-r--r-- fleker/_guest 2316 2017-07-19 19:41 google-assistant-sdk-0.3.3/googlesamples/assistant/library/hotword.py
-rw-r--r-- fleker/_guest 11361 2017-07-19 19:41 google-assistant-sdk-0.3.3/LICENSE
-rw-r--r-- fleker/_guest 67 2017-07-19 19:41 google-assistant-sdk-0.3.3/MANIFEST.in
-rw-r--r-- fleker/_guest 6340 2017-07-19 20:51 google-assistant-sdk-0.3.3/PKG-INFO
-rw-r--r-- fleker/_guest 4408 2017-07-19 19:41 google-assistant-sdk-0.3.3/README.rst
-rw-r--r-- fleker/_guest 93 2017-07-19 20:51 google-assistant-sdk-0.3.3/setup.cfg
-rw-r--r-- fleker/_guest 2769 2017-07-19 20:29 google-assistant-sdk-0.3.3/setup.py
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/tests/
drwxr-xr-x fleker/_guest 0 2017-07-19 20:51 google-assistant-sdk-0.3.3/tests/data/
-rw-r--r-- fleker/_guest 50288 2017-07-19 19:41 google-assistant-sdk-0.3.3/tests/data/whattimeisit.riff
-rw-r--r-- fleker/_guest 5112 2017-07-19 19:41 google-assistant-sdk-0.3.3/tests/test_audio_helpers.py
```

`google-assistant-sdk-0.3.3.tar.gz google-assistant-sdk-0.3.3/google_assistant_sdk.egg-info/requires.txt` has in it:

```
google-auth-oauthlib[tool]>=0.1.0

[samples]
google-assistant-grpc==0.0.2
google-auth-oauthlib==0.1.0
urllib3[secure]==1.21.1
sounddevice==0.3.7
click==6.7
tenacity==4.1.0
```

Is this some new/alternative way of doing what `requirements.txt` usually does?