Add GoCon and GothamGo to the conference list

Also list the conference cities to make it clearer where they are
held, since it's not always evident from the conference name.

README.md

@@ -942,11 +942,12 @@ Where to discover new Go libraries.
 
 ## Conferences
 
-* [dotGo](http://www.dotgo.io)
-* [GolangUK](http://www.golanguk.com/)
-* [GopherCon](http://www.gophercon.com/)
-* [GopherCon India](http://www.gophercon.in/)
-
+* [dotGo](http://www.dotgo.io) - Paris, France
+* [GoCon](http://gocon.connpass.com/) - Tokyo, Japan
+* [GolangUK](http://www.golanguk.com/) - London, UK
+* [GopherCon](http://www.gophercon.com/) - Denver, USA
+* [GopherCon India](http://www.gophercon.in/) - Bengaluru, India
+* [GothamGo](http://gothamgo.com/) - New York City, USA
 
 ## E-Books