HTTP 100 Continue

[t1gor]

Hello, guys.

I've encountered an intresting issue with the Response class. When I get the HTTP response containing HTTP/1.1 100 Continue status line, it breaks the response parser. See below for example request:

HTTP/1.1 100 Continue

HTTP/1.1 200 OK
Date: Tue, 10 Oct 2017 09:02:53 GMT
Server: Apache
X-SLR-RETRY-API: SetExpressCheckout
X-PAYPAL-OPERATION-NAME: SetExpressCheckout
X-PAYPAL-API-RC:
Connection: close
HTTP_X_PP_AZ_LOCATOR: sandbox.slc
Paypal-Debug-Id: e8abe44ddc3bd
Set-Cookie: X-PP-SILOVER=name%3DSANDBOX3.API.1%26silo_version%3D1880%26app%3Dappdispatcher_apit%26TIME%3D3196902489%26HTTP_X_PP_AZ_LOCATOR%3Dsandbox.slc; Expires=Tue, 10 Oct 2017 09:32:55 GMT; domain=.paypal.com; path=/; Secure; HttpOnly
Set-Cookie: X-PP-SILOVER=; Expires=Thu, 01 Jan 1970 00:00:01 GMT
Content-Length: 137
Content-Type: text/plain; charset=utf-8

TOKEN=EC%XXXXXXXXXXXXX&TIMESTAMP=2017%2d10%2d10T09%3a02%3a55Z&CORRELATIONID=XXXXXXXXXX&ACK=Success&VERSION=65%2e1&BUILD=XXXXXXXXXX

I am not entirely sure that 100 Continue responses should be handled that way, but I've created a pull request: #131

Would really appreciate some review and any thought on handling those responses.

Cheers.