v0.5.2 (2017-08-02)

This is a small update to make Drab compatible with Elixir 1.5.
Due to an issue with 1.5.0 (elixir-lang/elixir#6391) Elixir version is fixed on 1.4 or >= 1.5.1.

Fixes:

• #26, #27, #30, #31, #33