add check for python3-pip, service will not start without it

Author: Magnu5

examples/install-service.sh

@@ -19,6 +19,12 @@ if ! [ -f "/usr/bin/python3" ]; then
 	exit 1
 fi
 
+if ! [ -f "/usr/bin/python3-pip" ]; then
+	printf "Fan SHIM controller requires Python 3\n"
+	printf "You should run: 'sudo apt install python3'\n"
+	exit 1
+fi
+
 while [[ $# -gt 0 ]]; do
 	K="$1"
 	case $K in