Add yaml support for election

Instead of a simple txt file, we now use a yaml which is easier
	to detect if a user already made a vote or not.

src/main/java/org/jenkinsci/account/BoardElection.java

@@ -8,12 +8,18 @@ import org.kohsuke.stapler.interceptor.RequirePOST;
 
 import javax.naming.NamingException;
 import java.io.FileWriter;
+import java.io.FileReader;
+import java.io.File;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
+import java.util.Map;
+
+import com.esotericsoftware.yamlbeans.YamlReader;
+import com.esotericsoftware.yamlbeans.YamlWriter;
 
 /**
  * @author <a href="mailto:nicolas.deloof@gmail.com">Nicolas De Loof</a>
@@ -32,7 +38,9 @@ public class BoardElection {
         open = format.parse(params.electionOpen());
         close = format.parse(params.electionClose());
         candidates = params.electionCandidates().split(",");
-        log = params.electionLogfile();
+        log = params.electionLogDir() + "/" + params.electionClose().replaceAll("/","") + ".yaml";
+        File f = new File(log);
+        f.createNewFile();
     }
 
     @RequirePOST
@@ -52,11 +60,23 @@ public class BoardElection {
         for (String id : vote.split(",")) {
             selected.add(candidates[Integer.parseInt(id)]);
         }
-        String log = user.userId + ":" + StringUtils.join(selected, ",");
-        try (PrintWriter w = new PrintWriter(new FileWriter(log, true))) {
-            w.println(log);
+        // TODO build a nicer yaml structure document
+        YamlReader reader = new YamlReader(new FileReader(log));
+        Object object = new Object();
+        object = reader.read();
+        if (null == object){
+            String init_content = "election_close: " + close;
+            YamlReader init = new YamlReader(init_content);
+            object = init.read();
         }
 
+        Map map = (Map)object;
+        map.put(user.userId,StringUtils.join(selected, ","));
+
+        YamlWriter writer = new YamlWriter(new FileWriter(log, false));
+        writer.write(map);
+        writer.close();
+
         // TODO store
         return new HttpRedirect("done");
     }

src/main/java/org/jenkinsci/account/Parameters.java

@@ -37,7 +37,7 @@ public interface Parameters {
 
     String electionCandidates();
 
-    String electionLogfile();
+    String electionLogDir();
 
     String electionOpen();