force remove old bsp

Author: hathach

.travis.yml

@@ -27,11 +27,11 @@ before_install:
     - source install.sh
     # Remove release code and clone git master of nRF52
     - BSP_VERSION=`eval ls $BSP_PATH/nrf52`
-    - rm -r $BSP_PATH/nrf52/*
+    - rm -rf $BSP_PATH/nrf52/*
     - git clone --quiet https://github.com/adafruit/Adafruit_nRF52_Arduino.git $BSP_PATH/nrf52/$BSP_VERSION
     # Remove release code and clone git master of SAMD
     - BSP_VERSION=`eval ls $BSP_PATH/samd`
-    - rm -r $BSP_PATH/samd/*
+    - rm -rf $BSP_PATH/samd/*
     - git clone --quiet https://github.com/adafruit/ArduinoCore-samd.git $BSP_PATH/samd/$BSP_VERSION
 
 install: