Bump github.com/gliderlabs/ssh from 0.3.7 to 0.3.8

Bumps [github.com/gliderlabs/ssh](https://github.com/gliderlabs/ssh) from 0.3.7 to 0.3.8.
- [Release notes](https://github.com/gliderlabs/ssh/releases)
- [Commits](https://github.com/gliderlabs/ssh/compare/v0.3.7...v0.3.8

)

---
updated-dependencies:
- dependency-name: github.com/gliderlabs/ssh
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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