Use check instead of build in the CI

appveyor.yml

@@ -24,8 +24,8 @@ install:
 
 test_script:
   - if [%APPVEYOR_REPO_TAG%]==[false] (
-      cargo build --target %TARGET% &&
-      cargo build --target %TARGET% --release
+      cargo check --target %TARGET% &&
+      cargo check --target %TARGET% --release
     )
 
 before_deploy:

ci/script.sh

@@ -5,8 +5,8 @@ set -ex
 # TODO This is the "test phase", tweak it as you see fit
 main() {
     cargo fmt --all -- --check
-    cross build --target $TARGET
-    cross build --target $TARGET --release
+    cross check --target $TARGET
+    cross check --target $TARGET --release
 
     if [ ! -z $DISABLE_TESTS ]; then
         return