Fix cargo fmt for Travis

Stable Rust doesn't support `cargo fmt --check` (yet).

.travis.yml

@@ -2,10 +2,9 @@ language: rust
 cache: cargo
 rust:
   - stable
-  - beta
 before_script:
   - rustup component add rustfmt-preview
 script:
-  - cargo fmt --all -- --check
+  - cargo fmt --all -- --write-mode=check
   - cargo build --verbose
   - cargo test --verbose

examples/load.rs

@@ -5,10 +5,7 @@ extern crate log;
 
 extern crate error_chain;
 
-use electrs::{
-    bulk, config::Config, daemon::Daemon, errors::*, metrics::Metrics,
-    store::{DBStore},
-};
+use electrs::{bulk, config::Config, daemon::Daemon, errors::*, metrics::Metrics, store::DBStore};
 
 use error_chain::ChainedError;