Remove unnecessary workaround from setup.py

Also update MANIFEST.in to exclude files that shouldn't be in the sdist.

MANIFEST.in

@@ -11,4 +11,9 @@ global-exclude *.dll
 global-exclude *.pyc
 global-exclude *.pyo
 global-exclude *.so
+global-exclude coverage.xml
 
+prune docs/_build/
+
+include .coveragerc
+include .travis.yml

setup.py

@@ -18,12 +18,11 @@ from setuptools import setup, find_packages
 
 here = os.path.abspath(os.path.dirname(__file__))
 
+
 def _read_file(filename):
-    try:
-        with open(os.path.join(here, filename)) as f:
-            return f.read()
-    except IOError:  # Travis???
-        return ''
+    with open(os.path.join(here, filename)) as f:
+        return f.read()
+
 
 README = _read_file('README.rst') + '\n\n' + _read_file('CHANGES.rst')