fix: update microsoft provider api

[pringon]

This closes #58 and closes #59

Nice library, simple and intuitive client-facing API. 😄

I tried using the Microsoft provider but was getting the error described in the issues above. After some digging, I realised that the Microsoft Translator API has since been updated and the location of it has moved.

This PR contains the changes that got it working for me. Hope it helps!

An example of how to use the provider:

from translate import Translator

AZURE_TRANSLATE_SECRET = <your-api-key>

translator = Translator(
  to_lang="en", from_lang="autodetect", provider="microsoft",
  secret_access_key=AZURE_TRANSLATE_SECRET, region="europewest"
)

print(translator.translate("e pur si muove"))
# Output should be: and even though it moves

[terryyin]

Thanks! It looks like the API has changed quite a lot!