Allow retries in http client (#15)

Allow zero value for contextualized vars (#14)

Add ctx fork for concurrent access (#13)

Revert expected body check to allow nil reset (#12)

Add response body callback checker (#11)

Revert ioutil.ReadAll migration (#10)

Fix data race in Content-Type header (#9)

Add cookie jar to follow redirects (#8)

Add setters for query and form params (#7)

Use http.Client to follow redirects (#6)