Description
Make sure OSGi is supported
Add more test cases.
Karaf feature: cxf-rs-description-openapi-v3
Documentation: https://cwiki.apache.org/confluence/display/CXF20DOC/OpenApiFeature
OSGI sample: https://github.com/apache/cxf/tree/master/distribution/src/main/release/samples/jax_rs/description_openapi_v3_osgi