My fix for "; comment only lines"

This should fix #4 but there might be a better way.

Author: dglaude

adafruit_pioasm.py

@@ -60,6 +60,8 @@ def assemble(text_program):
     assembled = []
     for instruction in instructions:
         print(instruction)
+        if len(instruction) == 0:
+            continue
         instruction = instruction.split()
         delay = 0
         if instruction[-1].endswith("]"):  # Delay