change preload app author to 'card10 contributors'

preload/apps/bhi160/metadata.json

-{"author": "card10badge team", "name": "BHI160", "description": "Read BHI160 sensor data", "category": "Hardware", "revision": 1}
+{"author": "card10 contributors", "name": "BHI160", "description": "Read BHI160 sensor data", "category": "Hardware", "revision": -1, "source":"preload"}

preload/apps/ble/metadata.json

-{"author": "card10badge team", "name": "Bluetooth", "description": "Toggle Bluetooth Low Energy Indicator", "category": "Hardware", "revision": 1}
+{"author": "card10 contributors", "name": "Bluetooth", "description": "Toggle Bluetooth Low Energy Indicator", "category": "Hardware", "revision": -1, "source":"preload"}

preload/apps/ecg/metadata.json

-{"name":"ECG","description":"A simple ecg monitor which displays the heart rate and allows you to switch between usb and finger reader.","category":"hardware","author":"griffon","revision":1}
+{"name":"ECG","description":"A simple ecg monitor which displays the heart rate and allows you to switch between usb and finger reader.","category":"hardware","author":"card10 contributors","revision":-1,"source":"preload"}

preload/apps/personal_state/metadata.json

-{"author": "card10badge team", "name": "Personal State", "description": "Change the personal state LED", "category": "Hardware", "revision": 1}
+{"author": "card10 contributors", "name": "Personal State", "description": "Change the personal state LED", "category": "Hardware", "revision": -1, "source":"preload"}