Function easy_http_request::head

pub fn head<QK, QV, HK, HV>(
    url: &str, 
    query: Option<HashMap<QK, QV>>, 
    headers: Option<HashMap<HK, HV>>
) -> Result<HttpResponse, HttpRequestError> where
    QK: Eq + Hash + AsRef<str>,
    QV: AsRef<str>,
    HK: Eq + Hash + AsRef<str>,
    HV: AsRef<str>,