Add travis config

.travis.yml

@@ -0,0 +1,8 @@
+language: python
+python:
+  - "3.6.1"
+  - "3.7-dev"
+install:
+    - pip install .[tests]
+    - pip install coveralls
+script: pytest

README.rst

@@ -3,7 +3,13 @@
 PySecretHandshake - Secret Handshake in Python
 ==============================================
 
+|build-status|
+
 This module implements Secret Handshake as specified in Dominc Tarr's paper `"Designing a Secret Handshake: Authenticated
 Key Exchange as a Capability System" <http://dominictarr.github.io/secret-handshake-paper/shs.pdf>`_ (Dominic Tarr, 2015).
 
 **Please, don't use this package in production. The implementation hasn't yet been carefully checked.**
+
+.. |build-status| image:: https://travis-ci.org/pferreir/PySecretHandshake.svg?branch=master
+                   :alt: Travis Build Status
+                   :target: https://travis-ci.org/pferreir/PySecretHandshake