Rev version to 0.4.0.

Author: holetse

README.md

@@ -15,7 +15,7 @@ add additional support.
 ```elixir
 def deps do
   [{:distillery, "~> 1.3",
-   {:bootleg, "~> 0.3"}]
+   {:bootleg, "~> 0.4"}]
 end
 ```
 
@@ -399,7 +399,7 @@ for building phoenix releases.
 # mix.exs
 def deps do
   [{:distillery, "~> 1.3"},
-  {:bootleg, "~> 0.3"},
+  {:bootleg, "~> 0.4"},
   {:bootleg_phoenix, "~> 0.1"}]
 end
 ```

lib/mix/tasks/init.ex

@@ -42,7 +42,7 @@ defmodule Mix.Tasks.Bootleg.Init do
   #  # mix.exs
   #  def deps do
   #    [{:distillery, "~> 1.3"},
-  #    {:bootleg, "~> 0.3"},
+  #    {:bootleg, "~> 0.4"},
   #    {:bootleg_phoenix, "~> 0.1"}]
   #  end
   #  ```

mix.exs

@@ -1,7 +1,7 @@
 defmodule Bootleg.Mixfile do
   use Mix.Project
 
-  @version "0.3.0"
+  @version "0.4.0"
   @source "https://github.com/labzero/bootleg"
 
   def project do