Bug: string Infinity transformed to inf float when transforming to Pydantic model, which makes starlette to crash

[JoanFM]

Describe the bug

from jina import Document

d = Document()
d.tags['title'] = 'Infinity'

print(d.to_dict())

print(float('Infinity'))

this shows that it transforms to inf which makes starlette fail with:

Traceback (most recent call last):
  File "/home/joan/.local/lib/python3.7/site-packages/uvicorn/protocols/http/httptools_impl.py", line 371, in run_asgi
    result = await app(self.scope, self.receive, self.send)
  File "/home/joan/.local/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 59, in __call__
    return await self.app(scope, receive, send)
  File "/home/joan/.local/lib/python3.7/site-packages/fastapi/applications.py", line 270, in __call__
    await super().__call__(scope, receive, send)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/applications.py", line 124, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/middleware/errors.py", line 162, in __call__
    await self.app(scope, receive, _send)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/middleware/cors.py", line 84, in __call__
    await self.app(scope, receive, send)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/middleware/exceptions.py", line 79, in __call__
    raise exc
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/middleware/exceptions.py", line 68, in __call__
    await self.app(scope, receive, sender)
  File "/home/joan/.local/lib/python3.7/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
    raise e
  File "/home/joan/.local/lib/python3.7/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await self.app(scope, receive, send)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/routing.py", line 706, in __call__
    await route.handle(scope, receive, send)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/routing.py", line 276, in handle
    await self.app(scope, receive, send)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/routing.py", line 66, in app
    response = await func(request)
  File "/home/joan/.local/lib/python3.7/site-packages/fastapi/routing.py", line 264, in app
    response = actual_response_class(content, **response_args)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/responses.py", line 192, in __init__
    super().__init__(content, status_code, headers, media_type, background)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/responses.py", line 54, in __init__
    self.body = self.render(content)
  File "/home/joan/.local/lib/python3.7/site-packages/starlette/responses.py", line 200, in render
    separators=(",", ":"),
  File "/usr/lib/python3.7/json/__init__.py", line 238, in dumps
    **kw).encode(obj)
  File "/usr/lib/python3.7/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.7/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
ValueError: Out of range float values are not JSON compliant

I believe it may be related to:

pydantic/pydantic#1417