Fix circleci badge (#55)

[skip ci]

Author: Michele Mancioppi

README.md

@@ -1,5 +1,5 @@
+[![CircleCI](https://dl.circleci.com/status-badge/img/gh/lumigo-io/java-tracer/tree/master.svg?style=svg)](https://dl.circleci.com/status-badge/redirect/gh/lumigo-io/java-tracer/tree/master)
 ![Version](https://img.shields.io/badge/version-1.0.38-green.svg)
-[![CircleCI](https://circleci.com/gh/lumigo-io/java-tracer.svg?style=svg&circle-token=f2e3400e6e79bc31daeee1fc614ecc0a149b1905)](https://circleci.com/gh/lumigo-io/java-tracer)
 [![codecov](https://codecov.io/gh/lumigo-io/java-tracer/branch/master/graph/badge.svg?token=D3IZ5hQwaQ)](https://codecov.io/gh/lumigo-io/java-tracer)
 
 Supported Runtimes: Java 8, Java 11