[OWL-612] add http.HandleFunc(/api/platforms/)
[OWL-612] add http.HandleFunc(/api/platforms/)

Cepave/open-falcon-backend,Cepave/open-falcon-backend,masato25/query,masato25/open-falcon-backend,Cepave/query,Cepave/open-falcon-backend,Cepave/query,masato25/query,Cepave/open-falcon-backend,Cepave/query,masato25/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,masato25/query,Cepave/open-falcon-backend,masato25/query,masato25/open-falcon-backend,Cepave/query,masato25/open-falcon-backend,Cepave/open-falcon-backend