/**
* Return a frequency map of each letter in a string, ignores spaces.
* @param {string} str - a string
* @returns {Object} - the characters and their frequency
*
* ex: letterCount("hello world") //=> {h: 1, e: 1, l: 3, o: 2, w: 1, r: 1, d: 1}
*
*/
function letterCount() {}
module.exports = letterCount;