Update for 0.4 release

Author: sunchao

Cargo.toml

@@ -17,7 +17,7 @@
 
 [package]
 name = "parquet"
-version = "0.3.0"
+version = "0.4.0"
 license = "Apache-2.0"
 description = "Apache Parquet implementation in Rust"
 authors = [

README.md

@@ -23,7 +23,7 @@
 [![Coverage Status](https://coveralls.io/repos/github/sunchao/parquet-rs/badge.svg?branch=master)](https://coveralls.io/github/sunchao/parquet-rs?branch=master)
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![](http://meritbadge.herokuapp.com/parquet)](https://crates.io/crates/parquet)
-[![API docs](https://img.shields.io/badge/docs-0.3.0-blue.svg)](https://sunchao.github.io/parquet-rs/0.3.0/parquet/)
+[![API docs](https://img.shields.io/badge/docs-0.4.0-blue.svg)](https://sunchao.github.io/parquet-rs/0.4.0/parquet/)
 [![Master API docs](https://img.shields.io/badge/docs-master-green.svg)](https://sunchao.github.io/parquet-rs/master/parquet/)
 
 
@@ -33,7 +33,7 @@ An [Apache Parquet](https://parquet.apache.org/) implementation in Rust (work in
 Add this to your Cargo.toml:
 ```toml
 [dependencies]
-parquet = "0.3"
+parquet = "0.4"
 ```
 
 and this to your crate root: