Add Android Succinctly book.
Added Let's learn Go! - http://go-book.appspot.com

Added Let's learn Go! - http://go-book.appspot.com
Merge pull request #1058 from levibostian/android-succinctly

Add Android Succinctly book.
Merge pull request #1059 from sugatang-itlog/master

Added Let's learn Go! - http://go-book.appspot.com