Update target version from 8.0.16 to 8.0.17

Author: RoboraceMSW

pxt.json

@@ -17,7 +17,7 @@
         "test.ts"
     ],
     "targetVersions": {
-        "target": "8.0.16",
+        "target": "8.0.17",
         "targetId": "microbit"
     },
     "supportedTargets": [