Update README.md (#1040)

README.md

@@ -4,7 +4,6 @@
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/840351da141e4eaeac6476fd19ec0a33)](https://app.codacy.com/app/cvat/cvat?utm_source=github.com&utm_medium=referral&utm_content=opencv/cvat&utm_campaign=Badge_Grade_Dashboard)
 [![Gitter chat](https://badges.gitter.im/opencv-cvat/gitter.png)](https://gitter.im/opencv-cvat)
 [![Coverage Status](https://coveralls.io/repos/github/opencv/cvat/badge.svg?branch=)](https://coveralls.io/github/opencv/cvat?branch=develop)
-[![Maintainability](https://api.codeclimate.com/v1/badges/0461727199dfe049b2f1/maintainability)](https://codeclimate.com/github/opencv/cvat/maintainability)
 [![codebeat badge](https://codebeat.co/badges/53cd0d16-fddc-46f8-903c-f43ed9abb6dd)](https://codebeat.co/projects/github-com-opencv-cvat-develop)
 [![DOI](https://zenodo.org/badge/139156354.svg)](https://zenodo.org/badge/latestdoi/139156354)