Cycle object should accept an array

A Cycle object should accept an array and cycle through it as it would with a set of comma-separated objects.

```ruby
arr = [1,2,3]
cycle(arr) # => "1"
cycle(arr) # => "2"
cycle(arr) # => "3"
```

Previously, it would return the array as a string, because it took the array as a single object: 

```ruby
arr = [1,2,3]
cycle(arr) # => "[1,2,3]"
cycle(arr) # => "[1,2,3]"
cycle(arr) # => "[1,2,3]"
```