fix strategy test for api and linting (#1840)
### Summary
Closes unstructured-api issue
[188](https://github.com/Unstructured-IO/unstructured-api/issues/188)
The test and gist were using different versions of the same file
(jpg/pdf), creating what looked like a bug when there wasn't one. The
api is correctly using the `strategy` kwarg.
### Testing
#### Checkout to `main`
- Comment out the `@pytest.mark.skip` decorators for the
`test_partition_via_api_with_no_strategy` test
- Add an API key to your env:
- Add `from dotenv import load_dotenv; load_dotenv()` to the top of the
file and have `UNS_API_KEY` defined in `.env`
- Run `pytest test_unstructured/partition/test_api.py -k
"test_partition_via_api_with_no_strategy"`
^the test will fail
#### Checkout to this branch
- (make the same changes as above)
- Run `pytest test_unstructured/partition/test_api.py -k
"test_partition_via_api_with_no_strategy"`
### Other
`make tidy` and `make check` made linting changes to additional files
