Implement a function uniqueArray(arr) that removes all duplicate values from an array and returns a new array containing only unique values.

Examples

uniqueArray([1, 2, 2, 3, 4, 4, 5]); // [1, 2, 3, 4, 5]
uniqueArray(['a', 'b', 'a', 'c']); // ['a', 'b', 'c']
uniqueArray([1, 1, 1, 1]); // [1]