Bump Finagle version in Finagle and Finch benchmarks

[vkostyukov]

This RB bumps Finagle version to 6.34 in Finch and Finagle benchmarks.

Also,

• Circe version is bumped to 0.4.1 in Finch
• Scala version is bumped to 2.11.8 in both Finch and Finagle benchmarks

[NateBrady23]

That was fast! Thank you!

[NateBrady23]

finagle: setup.sh and framework processes have terminated
Server finagle: Framework processes have terminated
verify: 100% |############################################| Rough Time: 00:06:15
================================================================================
  Verification Summary

| Test: finagle
|       plaintext   : PASS
|       json        : PASS
================================================================================