• Performance improvement: removing 1 allocation by foregoing context.WithValue, thank you @bouk for
  your contribution (#555). Note: new benchmarks posted in README.
• middleware.CleanPath: new middleware that clean's request path of double slashes
• deprecate & remove chi.ServerBaseContext in favour of stdlib http.Server#BaseContext
• plus other tiny improvements, see full commit history below
• History of changes: see v4.1.2...v1.5.1