Use newer build tools package.

tannewt · tannewt · commit 31ca0a99a3bd · 2017-12-11T18:06:40.000-08:00
diff --git a/.travis.yml b/.travis.yml
@@ -22,7 +22,7 @@ deploy:
     tags: true
 
 install:
-  - pip install pylint circuitpython-travis-build-tools
+  - pip install pylint circuitpython-build-tools
 
 script:
   - pylint adafruit_register/*.py
