Bump src/executor, src/inigo

Bump cloudfoundry-incubator/executor:
  Alex Suraci:
     task registry rejects RunOnces with no stack ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/executor/builds/21053884 )
Bump cloudfoundry-incubator/inigo:
  Alex Suraci:
     always specify a stack in all RunOnces
     bump deps