Update to be compatible with the latest google-api-java-client(1.10.2)

Hey, I am new to github, not sure how this process works. Anyway, I changed some lines of your sample to adapt to the new api client, hope you don't mind. 

Changes are:
1. HttpRequest object use setHeaders/setParsers to set its attributes;
2. JsonHttpParser class is deprecated. Use JsonObjectParser instead;
3. create class-wide global instance of JacksonFactory class
4. HttpRequest object uses getUrl() to obtain the GenericUrl;
5. HttpResponseException class uses getStatusMessage to get error
message;