Move coverage to Codecov

Looks like a more reasonable alternative to Coveralls.

.travis.yml

@@ -23,10 +23,6 @@ addons:
             - bash-completion
             - mp3gain
 
-# Coverage reporting library.
-before_install:
-    - "[ ! -z $COVERAGE ] && travis_retry pip install coveralls || true"
-
 # To install dependencies, tell tox to do everything but actually running the
 # test.
 install:
@@ -35,10 +31,11 @@ install:
 
 script: tox -e $TOX_ENV
 
-# coveralls.io reporting, using https://github.com/coagulant/coveralls-python
-# Only report coverage for one version.
+# Report coverage to codecov.io.
+before_install:
+    - "[ ! -z $COVERAGE ] && travis_retry pip install codecov || true"
 after_success:
-    - "[ ! -z $COVERAGE ] && coveralls || true"
+    - "[ ! -z $COVERAGE ] && codecov || true"
 
 notifications:
     irc:

README.rst

@@ -1,8 +1,8 @@
 .. image:: https://travis-ci.org/sampsyo/beets.svg?branch=master
     :target: https://travis-ci.org/sampsyo/beets
 
-.. image:: http://img.shields.io/coveralls/sampsyo/beets.svg
-    :target: https://coveralls.io/r/sampsyo/beets
+.. image:: http://img.shields.io/codecov/c/github/sampsyo/beets.svg
+    :target: https://codecov.io/github/sampsyo/beets
 
 .. image:: http://img.shields.io/pypi/v/beets.svg
     :target: https://pypi.python.org/pypi/beets