It can be annoying to have to say raise_exc=False (or use try/except) on
every call when talking to an API where 4xx response codes are
useful/normal/informative or where the preferred coding style is to use
conditionals rather than try/except.
With this change, the Adapter constructor takes a new kwarg, raise_exc.
It defaults to None, and the existing behavior is unchanged. If set to
a boolean value, that is used as the default for requests. Specifying
raise_exc to the primitives (get, head, put, post, patch, delete,
request) at any point along the chain will still take precedence.
Change-Id: Ie291c3cb891467728d8ca33cf62afdab37c82f34
Closes-Bug: #1776501
51bfa030b1