upgrade fossa cli to latest and remove unused fossa.yml (#1196)

* fossa.yml is deprecated

* point fossa cli commandline to the latest

Author: shijiesheng

.buildkite/scripts/fossa.sh

@@ -2,7 +2,7 @@
 
 set -exo pipefail
 
-curl -H 'Cache-Control: no-cache' https://raw.githubusercontent.com/fossas/fossa-cli/master/install.sh | bash -s -- -b ~/
+curl -H 'Cache-Control: no-cache' https://raw.githubusercontent.com/fossas/fossa-cli/master/install-latest.sh | bash -s -- -b ~/
 
 ~/fossa analyze