chore(readme): remove Greenkeeper badge (#82)

Co-authored-by: greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>

Author: greenkeeper[bot]

README.md

@@ -1,6 +1,6 @@
 # Jest Playwright
 
-[![Greenkeeper badge](https://badges.greenkeeper.io/mmarkelov/jest-playwright.svg)](https://greenkeeper.io/)
+
 [![Coverage Status](https://coveralls.io/repos/github/mmarkelov/jest-playwright/badge.svg?branch=master)](https://coveralls.io/github/mmarkelov/jest-playwright?branch=master)
 
 Running your tests using [Jest](https://github.com/facebook/jest) & [Playwright](https://github.com/microsoft/playwright)