v0.6.7

Changed

• Updated dependencies.
  #271
  #270
  #273
  #278
  #279
  #281
  #285
• CI artifacts are now downloaded from https://ci-artifacts.rust-lang.org instead of https://s3-us-west-1.amazonaws.com/rust-lang-ci2 which should help with performance.

Fixed

• Fix bisecting into rollups via unrolled perf builds
  #280