Don't mark the build failed in case of decreased coverage

.github/workflows/tests.yml

@@ -49,3 +49,4 @@ jobs:
       - uses: coverallsapp/github-action@v2
         with:
           parallel-finished: true
+          fail-on-error: false

README.rst

@@ -3,13 +3,12 @@ pygelf
 |gh-actions| |coveralls| |pypi| |downloads|
 
 .. |gh-actions| image:: https://github.com/keeprocking/pygelf/actions/workflows/tests.yml/badge.svg?branch=master
-    :target: https://github.com/keeprocking/pygelf/actions
+   :target: https://github.com/keeprocking/pygelf/actions
 .. |pypi| image:: https://badge.fury.io/py/pygelf.svg
-    :target: https://pypi.python.org/pypi/pygelf
 .. |coveralls| image:: https://coveralls.io/repos/github/keeprocking/pygelf/badge.svg?branch=master
-    :target: https://coveralls.io/github/keeprocking/pygelf?branch=master
-.. |downloads| image:: https://pepy.tech/badge/pygelf/month
-    :target: https://pypi.python.org/pypi/pygelf
+   :target: https://coveralls.io/github/keeprocking/pygelf?branch=master
+.. |downloads| image:: https://img.shields.io/pypi/dm/pygelf
+   :target: https://pypi.python.org/pypi/pygelf
 
 Python logging handlers with GELF (Graylog Extended Log Format) support.