Added missing HTTP class methods on UnderOs::HTTP

Added the **post**, **put**, **delete**, **patch** and **head** methods to `UnderOs::HTTP` and I wrote some specs using the mocking framework [motion-facon](https://github.com/svyatogor/motion-facon).


_I am guessing that `UnderOs::HTTP::Request#build_request` needs to be updated before all of the HTTP verbs can be used?_

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##### Bonus
I also corrected `:sinner` -> `:spinner` in `UnderOs::UI::Locker`