Adds support for streaming responses to the core client and adds streaming support to the `post /completions` endpoint.

See `examples/streaming.py` for more detailed usage examples.

## Synchronous Usage

```py
response = client.completions.create(
    model="text-davinci-002",
    prompt="1,2,3,",
    max_tokens=5,
    temperature=0,
    stream=True,
)
for data in response:
    print(data.json())
```

## Asynchronous Usage

```py
response = await client.completions.create(
    model="text-davinci-002",
    prompt="1,2,3,",
    max_tokens=5,
    temperature=0,
    stream=True,
)
async for data in response:
    print(data.json())
```

* Add support for modifying files and file_set support (openai#4)

* Add support for modifying files and file_set support

* Bump version

* Updated file sets to use name everywhere

* Bump to 0.4.0

* Added cli support for file and fileset (openai#5)

* Added cli support for file and fileset

* Back to .4.0

* Typo

* Add some basic tests to confirm that array stuff works

* Added a test for multiple prompts.

* refactor retriever endpoint (openai#6)

* Make higherlevel have class methods so you can call with openai.HigherLevel.answer (openai#7)

* refactor retriever endpoint

* Actually just make everything a classmethod so you can call it like openai.HigherLevel

* Rename file_sets to collections everywhere (openai#8)

* Rename file_sets to collections everywhere

* Remove collections (openai#10)

* Higherlevel endpoints now point to /v1 (openai#11)

* Higherlevel endpoints now point to v1

* new line

* Move answer and classification to top level attributes, rename higherlevel (openai#12)

* Move answer and classification to top level attributes

* New namespaces for answers and classifications

* Meant to make the method create

* Go up the class stack since we don't need all the things that engineapiresource gives us

* Add file support to search (openai#13)

* Add file support to search

* Add support for max_rerank

* Added return_metadata support

* Fixed some cherry pick issues