Cleanup code

This changes variable names that were abbreviations, uses more constants
from the net/http package and improves the json decoding / encoding.

api/health.go

@@ -6,14 +6,14 @@ import (
 	"net/http"
 )
 
-// Health sends the response that the API works. If it
-// it is able to do so, it is obviously correct.
+// Health tries to respond that the server is alive.
+// If it is not, the response won't reach the client.
 func Health(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusOK)
 	w.Header().Set("Content-Type", "application/json")
 	response, err := json.Marshal(Message{"I'm alive!"})
 	if err != nil {
-		log.Printf("Error formatting the health route: %v\n", err)
+		log.Printf("JSON marshal error in health route: %v\n", err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 	}
 	if _, err := w.Write(response); err != nil {