Create bin directory for build jobs
Create bin directory for build jobs

This fixes a regression in commit 71e3bfc7: create bin directory before
we try to read it.

Signed-off-by: Sean Young <ed09b1b8de87fefa3fbdeb9d60effff215445504@monax.io>

eris-ltd/eris-db,silasdavis/burrow,silasdavis/burrow,silasdavis/burrow,eris-ltd/eris-db