Update to Rust 2018

- Fix deprecated Error::cause warnings and missing dyn
- Reset max_width
- Add rustfmt to Travis
- Run rustfmt on full codebase
 with `cargo fmt --all`
- Add rustfmt to Travis
- Complete migration to edition 2018
- Replace try! shorthand
- Use explicit `dyn Trait`

core/src/apresolve.rs

@@ -10,7 +10,7 @@ use std::str::FromStr;
 use tokio_core::reactor::Handle;
 use url::Url;
 
-error_chain!{}
+error_chain! {}
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct APResolveData {
@@ -21,7 +21,7 @@ fn apresolve(
     handle: &Handle,
     proxy: &Option<Url>,
     ap_port: &Option<u16>,
-) -> Box<Future<Item = String, Error = Error>> {
+) -> Box<dyn Future<Item = String, Error = Error>> {
     let url = Uri::from_str(APRESOLVE_ENDPOINT).expect("invalid AP resolve URL");
     let use_proxy = proxy.is_some();
 
@@ -52,19 +52,20 @@ fn apresolve(
         })
     });
     let body = body.then(|result| result.chain_err(|| "HTTP error"));
-    let body = body.and_then(|body| String::from_utf8(body).chain_err(|| "invalid UTF8 in response"));
+    let body =
+        body.and_then(|body| String::from_utf8(body).chain_err(|| "invalid UTF8 in response"));
 
-    let data =
-        body.and_then(|body| serde_json::from_str::<APResolveData>(&body).chain_err(|| "invalid JSON"));
+    let data = body
+        .and_then(|body| serde_json::from_str::<APResolveData>(&body).chain_err(|| "invalid JSON"));
 
     let p = ap_port.clone();
 
     let ap = data.and_then(move |data| {
         let mut aps = data.ap_list.iter().filter(|ap| {
             if p.is_some() {
-                Uri::from_str(ap)
-                    .ok()
-                    .map_or(false, |uri| uri.port().map_or(false, |port| port == p.unwrap()))
+                Uri::from_str(ap).ok().map_or(false, |uri| {
+                    uri.port().map_or(false, |port| port == p.unwrap())
+                })
             } else if use_proxy {
                 // It is unlikely that the proxy will accept CONNECT on anything other than 443.
                 Uri::from_str(ap)
@@ -86,7 +87,7 @@ pub(crate) fn apresolve_or_fallback<E>(
     handle: &Handle,
     proxy: &Option<Url>,
     ap_port: &Option<u16>,
-) -> Box<Future<Item = String, Error = E>>
+) -> Box<dyn Future<Item = String, Error = E>>
 where
     E: 'static,
 {