Add bitcore-message to modules list

I am not sure if the module must undergo some vetting process before
being added to the list of official Bitcore modules, but I have added it
here for when it is ready.

README.md

@@ -51,6 +51,7 @@ Module | Version | Building | Coverage
 [bitcore-ecies](http://github.com/bitpay/bitcore-ecies) | [![NPM Package](https://img.shields.io/npm/v/bitcore-ecies.svg?style=flat-square)](https://www.npmjs.org/package/bitcore-ecies) | [![Build Status](https://img.shields.io/travis/bitpay/bitcore-ecies.svg?branch=master&style=flat-square)](https://travis-ci.org/bitpay/bitcore-ecies) | [![Coverage Status](https://img.shields.io/coveralls/bitpay/bitcore-ecies.svg?style=flat-square)](https://coveralls.io/r/bitpay/bitcore-ecies)
 [bitcore-channel](http://github.com/bitpay/bitcore-channel) | [![NPM Package](https://img.shields.io/npm/v/bitcore-channel.svg?style=flat-square)](https://www.npmjs.org/package/bitcore-channel) | [![Build Status](https://img.shields.io/travis/bitpay/bitcore-channel.svg?branch=master&style=flat-square)](https://travis-ci.org/bitpay/bitcore-channel) | [![Coverage Status](https://img.shields.io/coveralls/bitpay/bitcore-channel.svg?style=flat-square)](https://coveralls.io/r/bitpay/bitcore-channel)
 [bitcore-explorers](http://github.com/bitpay/bitcore-explorers) | [![NPM Package](https://img.shields.io/npm/v/bitcore-explorers.svg?style=flat-square)](https://www.npmjs.org/package/bitcore-explorers) | [![Build Status](https://img.shields.io/travis/bitpay/bitcore-explorers.svg?branch=master&style=flat-square)](https://travis-ci.org/bitpay/bitcore-explorers) | [![Coverage Status](https://img.shields.io/coveralls/bitpay/bitcore-explorers.svg?style=flat-square)](https://coveralls.io/r/bitpay/bitcore-explorers)
+[bitcore-message](http://github.com/bitpay/bitcore-message) | [![NPM Package](https://img.shields.io/npm/v/bitcore-message.svg?style=flat-square)](https://www.npmjs.org/package/bitcore-message) | [![Build Status](https://img.shields.io/travis/bitpay/bitcore-message.svg?branch=master&style=flat-square)](https://travis-ci.org/bitpay/bitcore-message) | [![Coverage Status](https://img.shields.io/coveralls/bitpay/bitcore-message.svg?style=flat-square)](https://coveralls.io/r/bitpay/bitcore-message)
 
 ## Security
 

docs/index.md

@@ -42,6 +42,7 @@ Some functionality is implemented as a module that can be installed separately:
 * [Mnemonics](https://github.com/bitpay/bitcore-mnemonic)
 * [Elliptical Curve Integrated Encryption Scheme](https://github.com/bitpay/bitcore-ecies)
 * [Blockchain Explorers](https://github.com/bitpay/bitcore-explorers)
+* [Signed Messages](https://github.com/bitpay/bitcore-message)
 
 # Examples