Bump akka and blockmanager timeouts to 60 seconds

Occasionally people experience large GC pauses that cause timeout failures. This  bumps the timeout value to a fairly conservative length - 60 seconds - to avoid this. The trade-off is that if nodes fail during a job it will take a bit longer to detect it. That rarely happens, so I think it's a good trade-off.

Also, this sets spark.akka.timeout to equal the blockmanager timeout.