chore(deps): bump criterion from 0.2.5 to 0.2.8

[dependabot-preview]

Bumps criterion from 0.2.5 to 0.2.8.

Changelog

Sourced from criterion's changelog.

[0.2.8] - 2019-01-20

Changed

• Criterion.rs now uses rayon internally instead of manual unsafe code built with thread-scoped.
• Replaced handlebars templates with TinyTemplate
• Merged criterion-stats crate into criterion crate. criterion-stats will no longer receive
  updates.
• Replaced or removed various other dependencies to reduce the size of Criterion.rs' dependency
  tree.

[0.2.7] - 2018-12-29

Fixed

• Fixed version numbers to prevent incompatibilities between criterion and criterion-stats
  crates.

[0.2.6] - 2018-12-27 - Yanked

Added

• Added --list command line option, which lists the benchmarks but does not run them, to match
  cargo test -- --list.
• Added README/CONTRIBUTING/LICENSE files to sub-crates.
• Displays change in throughput in the command-line and HTML output as well as change in iteration
  time.
• Benchmarks with multiple functions and multiple values will now generate a per-value summary
  report file in addition to the existing per-function one.
• Added a --profile-time command-line argument which disables reporting and analysis and instead
  simply iterates each benchmark for approximately the given number of seconds. This supersedes the
  (now-deprecated) --measure-only argument.

Fixed

• Functions passed to Bencher::iter_with_large_setup can now return output. This is necessary to
  prevent the compiler from optimizing away the benchmark. This is technically a breaking change -
  that function requires a new type parameter. It's so unlikely to break existing code that I
  decided not to delay this for a breaking-change release.
• Reduced measurement overhead for the iter_with_large_setup and iter_with_drop methods.
• criterion_group and criterion_main macros no longer require the Criterion struct to be
  explicitly imported.
• Don't panic when gnuplot --version fails.
• Criterion.rs macros no longer require user to use criterion::Criterion;
• Criterion.rs no longer initializes a logger, meaning that it will no longer conflict with user
  code which does.
• Criterion.rs no longer fails to parse gnuplot version numbers like
  gnuplot 5.2 patchlevel 5a (Gentoo revision r0)
• Criterion.rs no longer prints an error message that gnuplot couldn't be found when chart
  generation is disabled (either by Criterion::without_plots, --noplot or disabling the
  HTML reports feature)
• Benchmark names are now automatically truncated to 100 characters and a number may be added to
  make them unique. This fixes a problem where gnuplot would crash if the title was extremely long,
  and also improves the general usability of Criterion.rs.

Changed

... (truncated)

Commits

• 9643f68 Bump version numbers.
• 022865d Add notice that criterion-plot is looking for a maintainer.
• 922339a Update to rand 0.6. Fixes #244.
• c4e8735 Add some utils for working with random numbers without the rand crate.
• cf0d86b Use lazy_static to cache the debug-mode flag
• f26070c Update dependencies. Fixes #255.
• f207369 Update changelog.
• 2c9937c Merge criterion-stats into criterion. Fixes #254
• bb8cedc Drop failure/failure-derive from criterion.
• eacef53 Drop failure/failure-derive from criterion-plot.
• Additional commits viewable in compare view

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