Add a couple of badges to README

Author: g-andrade

README.md

@@ -1,6 +1,7 @@
 # erlffx
 
------
+[![](https://img.shields.io/hexpm/v/erlffx.svg?style=flat)](https://hex.pm/packages/erlffx)
+[![](https://github.com/g-andrade/erlffx/workflows/build/badge.svg)](https://github.com/g-andrade/erlffx/actions?query=workflow%3Abuild)
 
 `erlffx` is an Erlang implementation of the mechanism described in the
 2010 paper [The FFX Mode of Operation for Format-Preserving

doc/overview-summary.html

@@ -10,7 +10,10 @@
 <h1>erlffx</h1>
 
 
-<hr>
+<p><a target="_parent" href="https://hex.pm/packages/erlffx" alt="Hex.pm Package">
+    <img src="https://img.shields.io/hexpm/v/erlffx.svg?style=flat"></a>
+<a target="_parent" href="https://github.com/g-andrade/erlffx/actions?query=workflow%3Abuild" alt="Travis CI Build Status">
+    <img src="https://github.com/g-andrade/erlffx/workflows/build/badge.svg"></a></p>
 
 <p><code>erlffx</code> is an Erlang implementation of the mechanism described in the 2010 paper <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.304.1736&amp;rep=rep1&amp;type=pdf">The FFX Mode of Operation for Format-Preserving Encryption</a> by Bellare, Rogaway and Spies. It is based on an existing <a href="https://github.com/michaeltandy/java-ffx-format-preserving-encryption">Java implementation</a> by Michael Tandy.</p>
 

doc/overview.edoc

@@ -1,7 +1,10 @@
 @title erlffx
 @doc
 
-<hr/>
+<a target="_parent" href="https://hex.pm/packages/erlffx" alt="Hex.pm Package">
+    <img src="https://img.shields.io/hexpm/v/erlffx.svg?style=flat"/></a>
+<a target="_parent" href="https://github.com/g-andrade/erlffx/actions?query=workflow%3Abuild" alt="Travis CI Build Status">
+    <img src="https://github.com/g-andrade/erlffx/workflows/build/badge.svg"/></a>
 
 `erlffx' is an Erlang implementation of the mechanism described in the 2010 paper <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.304.1736&amp;rep=rep1&amp;type=pdf">The FFX Mode of Operation for Format-Preserving Encryption</a> by Bellare, Rogaway and Spies. It is based on an existing <a href="https://github.com/michaeltandy/java-ffx-format-preserving-encryption">Java implementation</a> by Michael Tandy.