wellington formula

Hi, I would like to add the [wellington](https://github.com/wellington/wellington) project to brew.  I'm new to building formulas, so any help would be great.  I noticed that go get ./... does not work well with brew.  I took tips from the other go projects to explicitly require all packages as go_resources, including the main repo which has 5 packages in it.

Questions:

* This formula is dependent on libsass which requires compiling c code, did I properly mark that requirement?
* I'd like to alias this project to `wt` which is the name of the cli tool, how is that done?
This still can't get installed into `lib`, or it will conflict with the Homebrew-provided copy. If you're not statically linking libsass, this needs to get installed into a private location that will remain unlinked, like `libexec`.