Added .frozen to sys path to prefer frozen modules

Express class will now prefer frozen modules over local versions. This will
resolve memory allocation failures when including the entire library bundle
on the CPX.

Author: kattni

adafruit_circuitplayground/express.py

@@ -1,3 +1,6 @@
+import sys
+sys.path.insert(0, ".frozen")  # prefer frozen modules over local
+
 import adafruit_lis3dh
 import adafruit_thermistor
 import analogio