Beyond Functions in Elixir: Refactoring for Maintainability

There's some useful stuff in here for sure. If this is your own blog post here is some feedback.

- It contains a lot of very Phoenix-specific tips, that could be useful to have in the title.

- I see you linked to the docs in a number of places. This is great. Blog posts can rot quickly into outdated documentation.

- You mention using Phoenix 1.3. It might be nice to have that right at the top, so someone who stumbles on this in 2 years can determine whether it's relevant for what they're using.

- You have all these examples of writing a blog application. Would be great to have this blog post hosted on that application itself, rather than Medium! ;)