fix .travis.yml for single source file instead of directory

Author: dhalbert

.travis.yml

@@ -24,7 +24,7 @@ install:
 - pip install -r requirements.txt
 - pip install pylint circuitpython-build-tools Sphinx sphinx-rtd-theme
 script:
-- pylint adafruit_crickit/*.py
+- pylint adafruit_crickit.py
 - ([[ ! -d "examples" ]] || pylint --disable=missing-docstring,invalid-name,bad-whitespace
   examples/*.py)
 - circuitpython-build-bundles --filename_prefix adafruit-circuitpython-crickit --library_location