Updates for new rustfmt

.travis.yml

@@ -37,7 +37,7 @@ matrix:
       # skip the global install step
       install:
         - cargo install --debug --force rustfmt-nightly
-      script: cargo fmt -- --write-mode=diff
+      script: cargo fmt -- --check
 
 addons:
   apt:

src/diff.rs

@@ -23,7 +23,8 @@ pub fn get_git_diff(filename: &str) -> Option<LineChanges> {
     diff_options.pathspec(pathspec);
     diff_options.context_lines(0);
 
-    let diff = repo.diff_index_to_workdir(None, Some(&mut diff_options))
+    let diff = repo
+        .diff_index_to_workdir(None, Some(&mut diff_options))
         .ok()?;
 
     let mut line_changes: LineChanges = HashMap::new();

tests/tester.rs

@@ -29,10 +29,7 @@ impl BatTester {
 
     pub fn test_snapshot(&self, style: &str) {
         let output = Command::new(&self.exe)
-            .args(&[
-                "tests/snapshots/sample.rs",
-                &format!("--style={}", style),
-            ])
+            .args(&["tests/snapshots/sample.rs", &format!("--style={}", style)])
             .output()
             .expect("bat failed");
         // have to do the replace because the filename in the header changes based on the current working directory