[OWL-634] add http.HandleFunc(/api/hosts/)
[OWL-634] add http.HandleFunc(/api/hosts/)

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