Remove unnecessary visit on Channel

src/main/java/cz/cvut/fel/sit/omo/foodchain/channel/ChannelBase.java

@@ -107,8 +107,4 @@ public abstract class ChannelBase implements Observable {
     public ProductType getProductType() {
         return productType;
     }
-
-    public String accept(ReportTextVisitor visitor){
-        return visitor.visit(this);
-    }
 }

src/main/java/cz/cvut/fel/sit/omo/foodchain/reporting/FoodChainReportVisitor.java

@@ -12,11 +12,6 @@ public class FoodChainReportVisitor implements ReportTextVisitor {
         return null;
     }
 
-    @Override
-    public String visit(ChannelBase channel) {
-        return null;
-    }
-
     @Override
     public String visit(Product product) {
         return null;

src/main/java/cz/cvut/fel/sit/omo/foodchain/reporting/PartiesReportVisitor.java

@@ -12,11 +12,6 @@ public class PartiesReportVisitor implements ReportTextVisitor {
         return null;
     }
 
-    @Override
-    public String visit(ChannelBase channel) {
-        return null;
-    }
-
     @Override
     public String visit(Product product) {
         return null;

src/main/java/cz/cvut/fel/sit/omo/foodchain/reporting/ReportTextVisitor.java

@@ -13,8 +13,6 @@ public interface ReportTextVisitor {
 
     String visit(NodeBase node);
 
-    String visit(ChannelBase channel);
-
     String visit(Product product);
 
     String visit(ProductTransaction transaction);