Remove the whole blink example folder

This started failing in the Learning System Guides when I added
.generate files.

Author: jepler

Diff for: build_platform.py

@@ -40,8 +40,7 @@
 if "Adafruit_Learning_System_Guides" in BUILD_DIR:
     print("Found learning system repo")
     IS_LEARNING_SYS = True
-    os.remove(BUILD_DIR + "/ci/examples/Blink/Blink.ino")
-    os.rmdir(BUILD_DIR + "/ci/examples/Blink")
+    shutil.rmtree(BUILD_DIR + "/ci/examples/Blink")
 elif "METROX-Examples-and-Project-Sketches" in BUILD_DIR:
     print("Found MetroX Examples Repo")
     IS_LEARNING_SYS = True