build cplay_ble example with cplay bluefruit only

Author: hathach

libraries/Bluefruit52Lib/examples/Peripheral/cplay_ble/.build.cplaynrf52840

@@ -11,11 +11,11 @@
  All text above, and the splash screen below must be included in
  any redistribution
 *********************************************************************/
-#include <Adafruit_CircuitPlayground.h>
 #include <Adafruit_LittleFS.h>
 #include <InternalFileSystem.h>
 #include <bluefruit.h>
 #include <BLEAdafruitService.h>
+#include <Adafruit_CircuitPlayground.h>
 
 // BLE Service
 BLEDfu  bledfu;  // OTA DFU service

libraries/Bluefruit52Lib/examples/Peripheral/cplay_ble/.skip

@@ -67,7 +67,11 @@ def build_examples(variant):
     for sketch in glob.iglob('libraries/**/*.ino', recursive=True):
         start_time = time.monotonic()
 
-        if os.path.exists(os.path.dirname(sketch) + '/.skip') or os.path.exists(os.path.dirname(sketch) + '/.skip.' + variant):
+        # skip if example contains: ".skip" or ".skip.variant"
+        # however ".build.variant" file can overwrite ".skip", used to build a specific variant only
+        sketchdir = os.path.dirname(sketch)
+        if ( (os.path.exists(sketchdir + '/.skip') or os.path.exists(sketchdir + '/.skip.' + variant)) and
+                not os.path.exists(sketchdir + '/.build.' + variant)):
             success = "skipped"
         else:
             # TODO - preferably, would have STDERR show up in **both** STDOUT and STDERR.