Remove --write-mode=diff from the cargo call in the CI

appveyor.yml

@@ -45,7 +45,7 @@ install:
 test_script:
   # we don't run the "test phase" when doing deploys
   - if [%APPVEYOR_REPO_TAG%]==[false] (
-      cargo fmt --all -- --write-mode=diff &&
+      cargo fmt --all &&
       cargo build --target %TARGET% &&
       cargo build --target %TARGET% --release &&
       cargo test --target %TARGET% &&

ci/script.sh

@@ -4,7 +4,7 @@ set -ex
 
 # TODO This is the "test phase", tweak it as you see fit
 main() {
-    cargo fmt --all -- --write-mode=diff
+    cargo fmt --all
 
     cross build --target $TARGET
     cross build --target $TARGET --release