Update vesion select URLs in documentation (triton-inference-server#1582

)

Fix kfserving and documentation links

Update README and versions for 20.02 release

Update README and versions for 20.01 release

Update README and versions for 19.12 release

Update README and versions for 19.11 release

Skip backend-test-tools command

fix C++ API docs (triton-inference-server#699)

Force soft links to fix build issues (triton-inference-server#525)

Update README and versions for 19.07 release