Proxy settings feature added

[mkdadi]

This change is 

[jeremylow]

I have some concerns with this approach.

• requests can read proxy information from environment variables as explained here: http://docs.python-requests.org/en/master/user/advanced/#proxies , which seems like the simplest approach to adding proxy support since that's just a documentation change pointing out that that's available.

• rather than adding a new keyword argument to each method (and then remembering to do that on all future methods), we could do something where we add a proxies kwarg to the Api instantiation and then have that be available to Api._RequestUrl() etc. as self.proxies.

[mkdadi]

I agree that requests can read the proxy information from environment variables but if I want only this api to run through proxy I thought this would help. And yes you are correct rather that adding it to every method, it would have been better if an attribute is added to the class, Thanks.

[jeremylow]

Can we add inline documentation of this parameter to the docstring for the Api.__init__()method?

[mkdadi]

Inline documentation for the parameter has been added. Thanks.

[jeremylow]

Sorry - we do two spaces for docstrings. Other than that I'm good on this and we can get it merged.

[mkdadi]

Done 👍