drone CI badge in readme

.travis.yml

@@ -1,8 +1,8 @@
 language: python
 sudo: false
 python:
-    - "3.4"
     - "3.5"
+    - "3.6"
 
 install:
     - pip install -U wheel pytest==3

README.rst

@@ -6,6 +6,9 @@ larigira
     :target: https://travis-ci.org/boyska/larigira
     :alt: Build status
 
+.. image:: https://drone.degenerazione.xyz/api/badges/boyska/larigira/status.svg?branch=master
+    :alt: Build status on self-managed CI server
+
 .. image:: https://img.shields.io/pypi/v/larigira.svg
     :target: https://pypi.python.org/pypi/larigira
     :alt: Latest Version