Prepare Release v0.11.0

[Aneurysm9]

Added

• Top-level Version() and SemVersion() functions defining the current version of the contrib package. (Introduce a top-level Version() and SemVersion() function #225)
• Instrumentation for the github.com/astaxie/beego package. (feat: Add integration for github.com/astaxie/beego #200)
• Instrumentation for the github.com/bradfitz/gomemcache package. (Instrumentation for github.com/bradfitz/gomemcache #204)
• Host metrics instrumentation. (Host metrics instrumentation #231)
• Cortex histogram and distribution support. ([Cortex] Add support for histogram and distribution #237)
• Cortex example project. ([Cortex] Example project #238)
• Cortex HTTP authentication. ([cortex] Authentication Implementation and Timestamp Fix #246)

Changed

• Remove service name as a parameter of Sarama instrumentation. (Remove service name as a parameter of Sarama instrumentation #221)
• Replace WithTracer with WithTracerProvider in Sarama instrumentation. (Remove service name as a parameter of Sarama instrumentation #221)
• Switch to use common top-level module SemVersion() when creating versioned tracer in bradfitz/gomemcache. (Use top-level common SemVersion() in creation of versioned tracer for bradfitz/gomemcache #226)
• Use IntegrationShouldRun in gomemcache_test. (Use IntegrationShouldRun in gomemcache_test #254)
• Use Go 1.15 for CI builds. (Update build to use Go 1.15 #236)
• Improved configuration for runtime instrumentation. (Create runtime.Config struct with metric.Provider and WithMinimumReadMemStatsInterval() configuration options #224)

Fixed

• Update dependabot configuration to include newly added bradfitz/gomemcache package. (Use top-level common SemVersion() in creation of versioned tracer for bradfitz/gomemcache #226)
• Correct runtime instrumentation name. (Update runtime instrumentation Meter name #241)