Add codecov badge

.travis.yml

@@ -8,5 +8,5 @@ script:
 # - mypy --ignore-missing-imports .
 # - flake8 .
  - black --check
- - python -m pytest -v -cov=little_boxes
+ - python -m pytest -vv --cov=little_boxes
  - codecov

README.md

@@ -1,7 +1,7 @@
 # Little Boxes
 
-
 <a href="https://travis-ci.org/tsileo/little-boxes"><img src="https://travis-ci.org/tsileo/little-boxes.svg?branch=master" alt="Build Status"></a>
+<a href="https://codecov.io/gh/tsileo/little-boxes"><img src="https://codecov.io/gh/tsileo/little-boxes/branch/master/graph/badge.svg" /></a>
 <a href="https://github.com/tsileo/little-boxes/blob/master/LICENSE"><img src="https://img.shields.io/badge/license-ISC-blue.svg?style=flat" alt="License"></a>
 
 Tiny [ActivityPub](https://activitypub.rocks/) framework written in Python, both database and server agnostic.