Switch to codecov for coverage reports

This required some changes to work around the fact
that we run our tests from the tests/ directory in order
to ensure we import from the installed .whl file.  This
means that our .coveragerc file is not being sourced.

To fix that, I copy the .coverage data file to the top level
diretory, delete the coverage.xml file (which includes vendored files
we want to ignore), and let codecov regenerate the coverage.xml file.

I had to make a small change to the .coveragerc file to ignore
the botocore vendored packages.

Author: jamesls

.coveragerc

@@ -1,10 +1,10 @@
 [run]
 branch = True
-include =
-    botocore/*
 omit =
     botocore/vendored/*
 
 [report]
 exclude_lines =
     raise NotImplementedError.*
+include =
+    botocore/*

.travis.yml

@@ -11,8 +11,9 @@ before_install:
       echo "No pull requests can be sent to the master branch" 1>&2;
       exit 1;
     fi
+  - pip install codecov
 install:
   - python scripts/ci/install
 script: python scripts/ci/run-tests
 after_success:
-  - pip install python-coveralls && cd tests && coveralls
+  - rm tests/coverage.xml && mv tests/.coverage ./ && codecov

README.rst

@@ -4,6 +4,9 @@ botocore
 .. image:: https://secure.travis-ci.org/boto/botocore.png?branch=develop
    :target: http://travis-ci.org/boto/botocore
 
+.. image:: https://codecov.io/github/boto/botocore/coverage.svg?branch=develop
+    :target: https://codecov.io/github/boto/botocore?branch=develop
+
 
 A low-level interface to a growing number of Amazon Web Services. The
 botocore package is the foundation for the