getStore = (storeName, key = null) => {
  if (localStorage.getItem(storeName)) {
    const obj = JSON.parse(localStorage.getItem(storeName));
    if (!key) {
      return obj;
    }
    return obj[key] !== undefined ? obj[key] : null;
  }
  return null;
}
Get a value if the key and storeName is present. If the storeName is only present
then it return what is all keys on the store.
@param  {String} storeName  the name of the store.
@param  {String} [key=null] the key of the store. If the key is null by default.
@return {Object}            The Object with either just the value.