[aws_cpi] Change how args are passed to httpclient
[aws_cpi] Change how args are passed to httpclient

Commit cf6bd14fd1 in httpclient (included in 2.2.6) introduces a
change in delete requests allowing to have 'body'.

aws_cpi calls delete request with positional args, so if your bundle
includes httpclient >= 2.2.6 then httpclient doesn't recognize headers
(because it assumes it's the body of the request).

This commit changes how args are passed to httpclient, from
positional to hash based, so if in the future the httpclient gem
is upgraded it won't affect this code.

Change-Id: I97911ae391c35e4420b6c5b828e483ed7c2db757

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh