ensure requirements are installed

test_startup.sh

@@ -32,6 +32,8 @@ error=0
 check main.py || error=1
 for path in examples/*
 do
+    if test -f $path/requirements.txt; then
+        python3 -m pip install -r $path/requirements.txt || error=1 
     if test -f $path/start.sh; then
         check $path/start.sh dev || error=1 
     elif test -f $path/main.py; then