Fixed javadoc issues.

src/main/java/org/gitlab4j/api/GitLabApiException.java

@@ -151,10 +151,10 @@ public class GitLabApiException extends Exception {
     }
 
     /**
-     * Returns a Map<String, List<String>> instance containing validation errors if this GitLabApiException 
+     * Returns a Map&lt;String, List&lt;String&gt;&gt; instance containing validation errors if this GitLabApiException 
      * was caused by validation errors on the GitLab server, otherwise returns null.
      *
-     * @return a Map<String, List<String>> instance containing validation errors if this GitLabApiException 
+     * @return a Map&lt;String, List&lt;String&gt;&gt; instance containing validation errors if this GitLabApiException 
      * was caused by validation errors on the GitLab server, otherwise returns null
      */
     public Map<String, List<String>> getValidationErrors() {

src/main/java/org/gitlab4j/api/utils/JacksonJson.java

@@ -251,7 +251,7 @@ public class JacksonJson extends JacksonJaxbJsonProvider implements ContextResol
      * @return a JsonNode with the String parsed into a JSON tree
      * @throws IOException if any IO error occurs
      */
-    public static JsonNode toJsonNode(String json) throws IOException {
-        return (JacksonJsonSingletonHelper.JACKSON_JSON.objectMapper.readTree(json));
+    public static JsonNode toJsonNode(String jsonString) throws IOException {
+        return (JacksonJsonSingletonHelper.JACKSON_JSON.objectMapper.readTree(jsonString));
     }
 }