minor fix

scripts/grade.sh

@@ -9,13 +9,12 @@ BASEDIR=$(dirname "$0")
 source $BASEDIR/test_cases.sh
 source $BASEDIR/grade-utils.sh
 
-RUNNERS="cargo"
+RUNNER="cargo"
 
 # Lints.
 run_linters || exit 0
 
 # Executes test for each runner.
-for RUNNER in "${RUNNERS[@]}"; do
 echo "Running with $RUNNER..."
 echo "Below lines will show only failed tests."
 
@@ -25,7 +24,6 @@ for RUNNER in "${RUNNERS[@]}"; do
 
 # Runs tests.
 SCORE=$(run_tests)
-done
 
 echo Your score: ${SCORE}