Allow to set verbosity of output (Closes #26)

export/renderJSON.go

@@ -2,7 +2,6 @@ package export
 
 import (
 	"encoding/json"
-	"log"
 )
 
 // Render JSON output.
@@ -27,8 +26,8 @@ func (export *Export) renderJSON() (render string) {
 	}
 	renderBytes, err := json.Marshal(solutions)
 	if err != nil {
-		log.Println("ERROR: json.Marshal error:", err)
-		log.Println("Printing solution as-is:", solutions)
+		export.Controller.Outputter.Println("ERROR: json.Marshal error:", err)
+		export.Controller.Outputter.Println("Printing solution as-is:", solutions)
 		return ""
 	}
 	render = string(renderBytes)