Do not start syslog ourselves

It will be started automatically because it is in our applications. We
also should not include logger in our applications because we don't want
to start it before we start.

README.md

@@ -24,11 +24,12 @@ defp deps do
 end
 ```
 
-Add `:exsyslog` to your list of `included_applications`:
+Add `:exsyslog` to your list of `applications`, be sure to put it at the
+beginning, before `:logger` or anything that requires it:
 
 ```elixir
 def application do
-  [included_applications: [:exsyslog]]
+  [applications: [:exsyslog]]
 end
 ```
 

lib/ex_syslog.ex

@@ -11,7 +11,6 @@ defmodule ExSyslog do
   def init({__MODULE__, name}) do
     config = get_config(name, [])
 
-    :syslog.start()
     {:ok, log} = open_log(config)
 
     {:ok, %{name: name, log: log, config: config}}

mix.exs

@@ -16,7 +16,7 @@ defmodule Exsyslog.Mixfile do
   #
   # Type `mix help compile.app` for more information
   def application do
-    [applications: [:logger, :syslog, :poison]]
+    [applications: [:syslog, :poison]]
   end
 
   defp description do