Bump version to v0.3.0

Author: sheharyarn

README.md

@@ -35,7 +35,7 @@ through SafeURL:
 ```elixir
 def deps do
   [
-    {:safeurl, "~> 0.2.0"},
+    {:safeurl, "~> 0.3.0"},
     {:httpoison, "~> 1.8"},  # Optional
   ]
 end

mix.exs

@@ -4,7 +4,7 @@ defmodule SafeURL.MixProject do
 
   @app     :safeurl
   @name    "SafeURL"
-  @version "0.2.0"
+  @version "0.3.0"
   @github  "https://github.com/slab/safeurl-elixir"