message: change NoCache policy to just `max-age=0` to allow back-forward cache in the browser
diff: @@ -6,7 +6,7 @@ use iron::{
  };
  #[cfg(test)]
  -pub const NO_CACHE: &str = "no-cache, max-age=0";
  +pub const NO_CACHE: &str = "max-age=0";
  /// defines the wanted caching behaviour for a web response.
  pub enum CachePolicy {
  @@ -40,7 +40,7 @@ impl CachePolicy {
  pub fn render(&self, config: &Config) -> Vec<CacheDirective> {
  match *self {
  CachePolicy::NoCaching => {
  - vec![CacheDirective::NoCache, CacheDirective::MaxAge(0)]
  + vec![CacheDirective::MaxAge(0)]
  }
  CachePolicy::NoStoreMustRevalidate => {
  vec![
  @@ -118,7 +118,7 @@ mod tests {
  use iron::headers::CacheControl;
  use test_case::test_case;
  - #[test_case(CachePolicy::NoCaching, "no-cache, max-age=0")]
  + #[test_case(CachePolicy::NoCaching, "max-age=0")]
  #[test_case(
  CachePolicy::NoStoreMustRevalidate,
  "no-cache, no-store, must-revalidate, max-age=0"
  