Update Changelog and Readme for Release 0.3.1

Changelog.md

@@ -7,6 +7,7 @@
 * Introduce backends interface: PyAudio(), Dummy()
 * add device_info() helper function which prints audio device information in a tabular form
 * Bugfix #23: Add a small delay to server booting to prevent issues when Aserver and Arecorder are initialized back-to-back 
+* Helper function `record` has been dropped due to legacy reasons. An improved version will be introduced in 0.3.2.
 
 
 ## 0.3.0 (October 2019)

README.md

@@ -1,6 +1,6 @@
 [![Version](https://img.shields.io/badge/version-v0.3.1-orange.svg)](https://github.com/interactive-sonification/pya)
 [![PyPI](https://img.shields.io/pypi/v/pya.svg)](https://pypi.org/project/pya)
-[![GitHub commits](https://img.shields.io/github/commits-since/interactive-sonification/pya/v0.2.1.svg)](https://github.com/interactive-sonification/pya/compare/v0.3.1...master)
+[![GitHub commits](https://img.shields.io/github/commits-since/interactive-sonification/pya/v0.3.0.svg)](https://github.com/interactive-sonification/pya/compare/v0.3.0...master)
 [![License](https://img.shields.io/github/license/interactive-sonification/pya.svg)](LICENSE)
 [![Build Status Travis](https://travis-ci.org/interactive-sonification/pya.svg?branch=develop)](https://travis-ci.org/interactive-sonification/pya)
 [![Build status AppVeyor](https://ci.appveyor.com/api/projects/status/vn61qeri0uyxeedv/branch/develop?svg=true)](https://ci.appveyor.com/project/aleneum/pya-b7gkx/branch/develop)