vendor: update buildkit with typed errors support

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/opentracing/opentracing-go/README.md

@@ -8,8 +8,8 @@ This package is a Go platform API for OpenTracing.
 ## Required Reading
 
 In order to understand the Go platform API, one must first be familiar with the
-[OpenTracing project](http://opentracing.io) and
-[terminology](http://opentracing.io/documentation/pages/spec.html) more specifically.
+[OpenTracing project](https://opentracing.io) and
+[terminology](https://opentracing.io/specification/) more specifically.
 
 ## API overview for those adding instrumentation
 
@@ -27,7 +27,7 @@ The simplest starting point is `./default_tracer.go`. As early as possible, call
     import ".../some_tracing_impl"
 
     func main() {
-        opentracing.InitGlobalTracer(
+        opentracing.SetGlobalTracer(
             // tracing impl specific:
             some_tracing_impl.New(...),
         )
@@ -35,7 +35,7 @@ The simplest starting point is `./default_tracer.go`. As early as possible, call
     }
 ```
 
-##### Non-Singleton initialization
+#### Non-Singleton initialization
 
 If you prefer direct control to singletons, manage ownership of the
 `opentracing.Tracer` implementation explicitly.
@@ -161,3 +161,11 @@ Tracing system implementors may be able to reuse or copy-paste-modify the `basic
 ## API compatibility
 
 For the time being, "mild" backwards-incompatible changes may be made without changing the major version number. As OpenTracing and `opentracing-go` mature, backwards compatibility will become more of a priority.
+
+## Tracer test suite
+
+A test suite is available in the [harness](https://godoc.org/github.com/opentracing/opentracing-go/harness) package that can assist Tracer implementors to assert that their Tracer is working correctly.
+
+## Licensing
+
+[Apache 2.0 License](./LICENSE).