解决因生成javadoc失败导致Maven打包失败问题

方案就是设置javadoc生成失败时不导致整个打包失败：

             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
                 <version>2.8</version>
                 <executions>
                     <execution>
                         <id>attach-javadocs</id>
                         <goals>
                             <goal>jar</goal>
                         </goals>
                         <configuration>
                             <failOnError>false</failOnError>
                         </configuration>
                     </execution>
                 </executions>
             </plugin>