fix: All examples should work on CPU and GPU now

tests/test_examples.sh

@@ -5,7 +5,7 @@ failed=0
 for example in $(find $1 -maxdepth 1 -name "*.py")
 do
     echo  -n "$x" $example '... '
-    export DISPLAY= && python $example --fast_dev_run 1 &> run_log.txt
+    export DISPLAY= && python $example --fast_dev_run 1 --gpus 0 &> run_log.txt
     if [[ $? -ne 0 ]]; then
         echo "FAILED!!"
         cat run_log.txt