Unit testing. MemoryRange work.

src/main/java/com/loomcom/lm6502/MemoryRangeException.java

@@ -0,0 +1,10 @@
+package com.loomcom.lm6502;
+
+/**
+ * Exception that will be thrown if devices conflict in the IO map.
+ */
+class MemoryRangeException extends Exception {
+	public MemoryRangeException(String msg) {
+		super(msg);
+	}
+}