[ADMIN] Add FOSSA badges (open-telemetry#529)

Author: marcalff

README.md

@@ -1,5 +1,8 @@
 # OpenTelemetry C++ Contrib
 
+[![FOSSA License Status](https://app.fossa.com/api/projects/custom%2B162%2Fgithub.com%2Fopen-telemetry%2Fopentelemetry-cpp-contrib.svg?type=shield&issueType=license)](https://app.fossa.com/projects/custom%2B162%2Fgithub.com%2Fopen-telemetry%2Fopentelemetry-cpp-contrib?ref=badge_shield&issueType=license)
+[![FOSSA Security Status](https://app.fossa.com/api/projects/custom%2B162%2Fgithub.com%2Fopen-telemetry%2Fopentelemetry-cpp-contrib.svg?type=shield&issueType=security)](https://app.fossa.com/projects/custom%2B162%2Fgithub.com%2Fopen-telemetry%2Fopentelemetry-cpp-contrib?ref=badge_shield&issueType=security)
+
 This repository contains set of components extending functionality of the
 OpenTelemetry SDK. Instrumentation libraries, exporters, and other components
 can find their home here.