Bump src/app-manager, src/converger, src/etcd, src/executor, src/inigo, src/rep, src/runtime-metrics-server, src/stager

Bump cloudfoundry-incubator/app-manager:
  Alex Suraci:
     pass stack through to LRP ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/app-manager/builds/25180126 )
     deps ( Travis Unknown )
Bump cloudfoundry-incubator/converger:
  Alex Suraci:
     godeps ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/converger/builds/25180798 )
Bump coreos/etcd:
  Brandon Philips:
     Merge pull request #779 from unihorn/89 ( Travis Unknown )
  Yicheng Qin:
     chore(standby_server): let syncInterval represent in second unit ( Travis Unknown )
     fix(simple_snapshot_test): enlarge reasonable index range ( Travis Unknown )
     chore(standby): minor changes based on comments ( Travis Unknown )
     chore(cluster_config): set default timeout to 5s ( Travis Unknown )
     bump(goraft/raft): c76c5d95 ( Travis Unknown )
     feat(cluster_config): change field from int to float64 ( Travis Unknown )
     chore(standby): minor changes based on comments ( Travis Unknown )
     feat(option): add cluster config option ( Travis Unknown )
     chore(cluster_config): rename SyncClusterInterval to SyncInterval ( Travis Unknown )
     refactor(find_cluster): make it simpler ( Travis Unknown )
     feat: implement standby mode ( Travis Unknown )
     docs(standbys): specification for standby module ( Travis Unknown )
Bump cloudfoundry-incubator/executor:
  Alex Suraci:
     godeps ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/executor/builds/25180754 )
     add no-op defaults to fake client ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/executor/builds/25178450 )
Bump cloudfoundry-incubator/inigo:
  Alex Suraci:
     specify stack in app runner test
     godeps, rename run_once_test to task_test
Bump cloudfoundry-incubator/rep:
  Alex Suraci:
     deps ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/rep/builds/25178591 )
     verify LRP stack matches configured stack ( Travis Unknown )
Bump cloudfoundry-incubator/runtime-metrics-server:
  Alex Suraci:
     bump deps
     depointerify
Bump cloudfoundry-incubator/stager:
  Momchil Atanasov:
     Refactor inbox test ( Travis created: https://travis-ci.org/cloudfoundry-incubator/stager/builds/25181231 )