pg:blocking query is old

[keiko713]

I believe that the query of pg:blocking came from following page (looking at https://github.com/heroku/heroku-pg-extras/issues/80): https://wiki.postgresql.org/wiki/Lock_Monitoring

However, the query definitely changed. Looking at Japanese version of that page, the query is very similar to "if Postgres version is below 9.2", and Heroku Postgres doesn't have 9.2 anymore so we should update it to up-to-date one. https://github.com/heroku/heroku-pg-extras/blob/07cda801f3368676afd54b6fee8b2874f3487701/commands/blocking.js#L8-L21

[chrismo]

Sad to see such an old issue for this. I'd love to see this fixed.