change 'travis-ci.org' to 'travis-ci.com'

Author: sommersoft

README.rst

@@ -9,8 +9,8 @@ Introduction
     :target: https://discord.gg/nBQh6qu
     :alt: Discord
 
-.. image:: https://travis-ci.org/adafruit/Adafruit_CircuitPython_PN532.svg?branch=master
-    :target: https://travis-ci.org/adafruit/Adafruit_CircuitPython_PN532
+.. image:: https://travis-ci.com/adafruit/Adafruit_CircuitPython_PN532.svg?branch=master
+    :target: https://travis-ci.com/adafruit/Adafruit_CircuitPython_PN532
     :alt: Build Status
 
 CircuitPython driver for the `PN532 NFC/RFID Breakout <https://www.adafruit.com/product/364>`_ and `PN532 NFC/RFID Shield <https://www.adafruit.com/product/789>`_