Fix CI script for acceptance tests, and have them run in parallel.

examples/acceptance_tests/ci

@@ -2,11 +2,18 @@
 
 exit_codes=()
 
-for scenario in $(find . -maxdepth 1 -mindepth 1 -regex ".*[0-9]\{3\}" -type d); do
-    ./run $scenario
-    exit_codes+=("$?")
+TESTS=()
+for scenario in $(find . -maxdepth 1 -mindepth 1 -type d ! -name script_context); do
+  ./run $scenario &
+  TESTS+=("$!")
 done
 
+for p in ${TESTS[@]}; do
+  wait $p
+  exit_codes+=("$?")
+done
+
+
 for interaction in $(find script_context/validators -type f); do
   title=$(basename $interaction)
   title="${title%.*}"
@@ -17,6 +24,7 @@ done
 
 for code in ${exit_codes[@]}; do
   if [ $code -ne 0 ]; then
+    echo "Some test returned non-zero code: $code"
     exit $code
   fi
 done