Write a function called letter_count in a file words.py that takes two string arguments. The first string is a bunch of text, and the second is a letter. The function returns the number of occurrences of the letter in the text. Your function should be case insensitive, that is: halLway should return 2 for ('halLway','l') and ('halLway','L').

using python 2.7 make the letter counting code