Adding tests for upload and download with progress
#update - cURL representation should included additional headers in NSURLSessionConfiguration
[Issue #146] Fixing encoding of ampersands and adding test for ampersands in key and value of query parameter
Changing upload and download tests to cancel after first progress block call to ensure that fulfill is called at most once
[Issue #146] Adding test for question marks in url encoded query
Update README.md
Merge pull request #140 from rynecheow/master

cURL representation should included additional headers in NSUR...
Update README.md
fixes bug with HTTPbody parameters being encoded twice
Merge pull request #153 from kaphacius/master

fixes bug with HTTPbody parameters being encoded twice
Removing extraneous dispatch to background and using weak reference for delegate in response