Check for bebop ip as environment variable

Tools/adb_upload_to_bebop.sh

@@ -1,6 +1,12 @@
 #!/bin/bash
 
-ip=192.168.42.1
+if [ -z ${BEBOP_IP+x} ]; then 
+  ip=192.168.42.1
+  echo "\$BEBOP_IP is not set (use default: $ip)"
+else 
+  ip=$BEBOP_IP
+  echo "\$BEBOP_IP is set to $ip"
+fi
 port=9050
 
 echo "Connecting to bebop: $ip:$port"