release new minor version for updated gun dependency

Author: suazithustra

Diff for: README.md

@@ -136,7 +136,7 @@ iex> Arangox.options(conn, "/")
 ```elixir
 def application() do
   [
-    extra_applications: [:logger, :gun])
+    extra_applications: [:logger, :gun]
   ]
 end
 ```

Diff for: mix.exs

@@ -1,7 +1,7 @@
 defmodule Arangox.MixProject do
   use Mix.Project
 
-  @version "0.5.6"
+  @version "0.6.0"
   @description """
   ArangoDB 3.4+ driver for Elixir with connection pooling, support for \
   VelocyStream, active failover, transactions and streamed cursors.