Prepare 3.0.0 release (#111)

Author: kp-cat

README.md

@@ -24,7 +24,7 @@ ConfigCat is a [hosted feature flag service](http://configcat.com). Manage featu
 ```elixir
 def deps do
   [
-    {:configcat, "~> 2.0.0"}
+    {:configcat, "~> 3.0.0"}
   ]
 end
 ```

lib/config_cat/hooks.ex

@@ -54,9 +54,9 @@ defmodule ConfigCat.Hooks do
   end
 
   @typedoc """
-  A module/function name/extra arguments tuple representing a callback function.
+  A hook callback is either an anonymous function or a module/function name/extra_arguments tuple.
 
-  Each callback passes specific arguments. These specific arguments are
+  Each callback is passed specific arguments. These specific arguments are
   prepended to the extra arguments provided in the tuple (if any).
 
   For example, you might want to define a callback that sends a message to

mix.exs

@@ -9,7 +9,7 @@ defmodule ConfigCat.MixProject do
       name: "ConfigCat",
       source_url: @source_url,
       homepage_url: "https://configcat.com/",
-      version: "2.0.1",
+      version: "3.0.0",
       elixir: "~> 1.10",
       description: description(),
       package: package(),