update readme

Author: ardunn

README.md

@@ -1,6 +1,6 @@
 
 # <img alt="rocketsled" src="docs_rst/_static/rsfw.png" width="400">
-[![build shield](https://circleci.com/gh/hackingmaterials/rocketsled/tree/master.svg?style=shield&circle-token=83bfd1d89c4c599435dc358fc7c54243af40b503)](https://circleci.com/gh/hackingmaterials/rocketsled)
+[![CircleCI](https://circleci.com/gh/hackingmaterials/rocketsled.svg?style=svg)](https://circleci.com/gh/hackingmaterials/rocketsled)
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/3e4e2ac81f8d47c58759c386a6377e7d)](https://www.codacy.com/app/ardunn/rocketsled?utm_source=github.com&amp;utm_medium=referral&amp;utm_content=hackingmaterials/rocketsled&amp;utm_campaign=Badge_Grade)
 [![Codacy Badge](https://api.codacy.com/project/badge/Coverage/3e4e2ac81f8d47c58759c386a6377e7d)](https://www.codacy.com/app/ardunn/rocketsled?utm_source=github.com&utm_medium=referral&utm_content=hackingmaterials/rocketsled&utm_campaign=Badge_Coverage)