Do a cargo check instead of duplicating the build

ci/script.sh

@@ -4,7 +4,7 @@ set -ex
 
 # TODO This is the "test phase", tweak it as you see fit
 main() {
-    cross build --target $TARGET
+    cross check
     cross build --target $TARGET --release
 
     if [ ! -z $DISABLE_TESTS ]; then
@@ -12,7 +12,6 @@ main() {
     fi
 
     cross test --target $TARGET
-    cross test --target $TARGET --release
 }
 
 # we don't run the "test phase" when doing deploys