Pass tests for Python 3.7

- Don't include compiled files into package.
- Install the newest setuptools to properly
  install package.

.travis.yml

@@ -16,6 +16,7 @@ python:
 before_install: sudo apt-get install libxml2-dev libxslt-dev
 # command to install dependencies
 install:
+  - pip install -U pip wheel setuptools
   - python setup.py install
   - make deps
 # command to run tests

MANIFEST.in

@@ -2,3 +2,5 @@ include README.rst
 include CHANGELOG.rst
 include LICENSE.rst
 include AUTHORS.txt
+recursive-exclude * __pycache__
+recursive-exclude * *.py[co]