.travis.yml refresh

- Update to xenial
- Remove unused pandoc dependency
- Run our (currently very minimal) test suite

.travis.yml

@@ -1,4 +1,4 @@
-dist: trusty
+dist: xenial
 sudo: false
 
 language: python
@@ -7,12 +7,10 @@ python:
   - '3.5'
   - '3.6'
 
-script: python3 -m compileall .
-
-addons:
-  apt:
-    packages:
-    - pandoc
+install: python3 setup.py install
+script:
+  - python3 -m compileall .
+  - cd test/ && python3 -m unittest *.py
 
 deploy:
   provider: pypi