Release of version 0.4.0 of EOSRPC

This release includes:

- New error handling strategy
- Improved compatibility with EOS RPC 1.2
- Logger for request error

EOSRPC no longer throws exceptions as the default. Now it returns the result
tuples: `{:ok, result}` for successful execution and `{:error, reason}` for
errors

If you want EOS RPC to throw exceptions, you should use the `!` variation, all
functions have been updated to support it

EOS RPC merged `account_history` and `history` APIs, and so did EOSRPC, now all
history related endpoints are on `EOSRPC.History` just as the official
documentation for EOS RPC interface

EOSRPC now logs all failures that are called with the bang variation (`!`). It
can help on production debugging. It uses Elixir default Logger library

Author: lucca65

mix.exs

@@ -4,7 +4,7 @@ defmodule EOSRPC.Mixfile do
   def project do
     [
       app: :eosrpc,
-      version: "0.3.0",
+      version: "0.4.0",
       elixir: "~> 1.5",
       start_permanent: Mix.env() == :prod,
       description: "Simple EOSRPC Wrapper for Elixir",