update badges to codecov

HOWTOCONTRIBUTE.rst

@@ -150,12 +150,6 @@ Preparing Pull Requests
 
     $ pytest xskillscore
 
-   Check that your contribution is covered by tests and therefore increases the overall test coverage::
-
-    $ coverage run --source xskillscore -m py.test
-    $ coverage report
-    $ coveralls
-
   Please stick to `xarray <http://xarray.pydata.org/en/stable/contributing.html>`_'s testing recommendations.
 
 #. Running the performance test suite

README.rst

@@ -3,18 +3,26 @@ xskillscore: Metrics for verifying forecasts
 
 .. image:: https://travis-ci.org/xarray-contrib/xskillscore.svg?branch=master
    :target: https://travis-ci.org/xarray-contrib/xskillscore
+
 .. image:: https://img.shields.io/pypi/v/xskillscore.svg
    :target: https://pypi.python.org/pypi/xskillscore/
+
 .. image:: https://anaconda.org/conda-forge/xskillscore/badges/version.svg
    :target: https://anaconda.org/conda-forge/xskillscore/
-.. image:: https://coveralls.io/repos/github/xarray-contrib/xskillscore/badge.svg?branch=master
-   :target: https://coveralls.io/github/xarray-contrib/xskillscore?branch=master
+
+
+.. image:: https://codecov.io/gh/xarray-contrib/xskillscore/branch/master/graph/badge.svg?token=KB5FZNIO8W
+   :target: https://codecov.io/gh/xarray-contrib/xskillscore
+
 .. image:: https://img.shields.io/readthedocs/xskillscore/stable.svg?style=flat
    :target: https://xskillscore.readthedocs.io/en/stable/?badge=stable
+
 .. image:: https://img.shields.io/badge/benchmarked%20by-asv-green.svg?style=flat
    :target: https://raybellwaves.github.io/xskillscore/
+
 .. image:: https://img.shields.io/conda/dn/conda-forge/xskillscore.svg
    :target: https://anaconda.org/conda-forge/xskillscore
+
 .. image:: https://mybinder.org/badge_logo.svg
  :target: https://mybinder.org/v2/gh/raybellwaves/xskillscore-tutorial/master?urlpath=lab
 

docs/source/index.rst

@@ -10,9 +10,9 @@ xskillscore: Metrics for verifying forecasts
 .. image:: https://anaconda.org/conda-forge/xskillscore/badges/version.svg
    :target: https://anaconda.org/conda-forge/xskillscore/
 
-.. image:: https://coveralls.io/repos/github/xarray-contrib/xskillscore/badge.svg?branch=master
-   :target: https://coveralls.io/github/xarray-contrib/xskillscore?branch=master
-
+.. image:: https://codecov.io/gh/xarray-contrib/xskillscore/branch/master/graph/badge.svg?token=KB5FZNIO8W
+   :target: https://codecov.io/gh/xarray-contrib/xskillscore
+    
 .. image:: https://img.shields.io/badge/benchmarked%20by-asv-green.svg?style=flat
    :target: https://raybellwaves.github.io/xskillscore/