Remove activesupport dependency

[project-eutopia]

Required changes:

• Implement Array.split
• Implement Array.wrap
• Implement Object.present? and Object.blank?
• Implement String.underscore
• Change try to safe navigation operator &.

[shioyama]

Rather than monkey-matching core classes, I'd recommend creating a separate class which has all the methods and calling them explicitly, like this.

[project-eutopia]

@shioyama Thanks for the helpful comment. I agree with your suggestion 👍

I knew some of the above methods were ActiveSupport features, but some I was surprised about. In particular I wish Array.split was a native Ruby method, as it fits nicely along with String.split.

[shioyama]

I learned that you can get the same result as Array.wrap(...) by just calling Array(...). Array is actually a method on Kernel. Neat eh?

[project-eutopia]

That is neat, and it would work here. Reading up it seems that the notation [*to_be_wrapped] is equivalent to Array(to_be_wrapped), but I would prefer using Array.

[project-eutopia]

@shioyama Thanks for your helpful advice. I removed the dependency in #78