Bump src/app-manager

Bump cloudfoundry-incubator/app-manager:
  Alex Suraci:
     Remove nats flags ( Travis created: https://travis-ci.org/cloudfoundry-incubator/app-manager/builds/27512048 )
     extract nsync ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/app-manager/builds/27450213 )