Make locale optional also Fixes #27

[isik-kaplan]

Hey there,

According to the documentation the locale and conversationId parameters are optional, yet python sdk can't seem to handle the optional values. and the issue related is almost 4 years old. Am I missing something, is there a newer sdk that we are supposed to use?

Also, I just re-wrote the function I was currently having problems with for a small and atomic PR, but the whole sdk would be a lot cleaner with a simple urllib.parse.urlencode, don't you think? Would save a lot of code, would be a lot less verbose.