swarm: integrate OpenTracing; propagate ctx to internal APIs (#17169)

* swarm: propagate ctx, enable opentracing

* swarm/tracing: log error when tracing is misconfigured

vendor/github.com/uber/jaeger-client-go/glide.lock

@@ -0,0 +1,89 @@
+hash: 3accf84f97bff4a91162736104c0e9b9790820712bd86db6fec5e665f7196a82
+updated: 2018-04-30T11:46:43.804556-04:00
+imports:
+- name: github.com/beorn7/perks
+  version: 3a771d992973f24aa725d07868b467d1ddfceafb
+  subpackages:
+  - quantile
+- name: github.com/codahale/hdrhistogram
+  version: 3a0bb77429bd3a61596f5e8a3172445844342120
+- name: github.com/crossdock/crossdock-go
+  version: 049aabb0122b03bc9bd30cab8f3f91fb60166361
+  subpackages:
+  - assert
+  - require
+- name: github.com/davecgh/go-spew
+  version: 8991bc29aa16c548c550c7ff78260e27b9ab7c73
+  subpackages:
+  - spew
+- name: github.com/golang/protobuf
+  version: bbd03ef6da3a115852eaf24c8a1c46aeb39aa175
+  subpackages:
+  - proto
+- name: github.com/matttproud/golang_protobuf_extensions
+  version: c12348ce28de40eed0136aa2b644d0ee0650e56c
+  subpackages:
+  - pbutil
+- name: github.com/opentracing/opentracing-go
+  version: 1949ddbfd147afd4d964a9f00b24eb291e0e7c38
+  subpackages:
+  - ext
+  - log
+- name: github.com/pkg/errors
+  version: 645ef00459ed84a119197bfb8d8205042c6df63d
+- name: github.com/pmezard/go-difflib
+  version: 792786c7400a136282c1664665ae0a8db921c6c2
+  subpackages:
+  - difflib
+- name: github.com/prometheus/client_golang
+  version: c5b7fccd204277076155f10851dad72b76a49317
+  subpackages:
+  - prometheus
+- name: github.com/prometheus/client_model
+  version: 99fa1f4be8e564e8a6b613da7fa6f46c9edafc6c
+  subpackages:
+  - go
+- name: github.com/prometheus/common
+  version: 38c53a9f4bfcd932d1b00bfc65e256a7fba6b37a
+  subpackages:
+  - expfmt
+  - internal/bitbucket.org/ww/goautoneg
+  - model
+- name: github.com/prometheus/procfs
+  version: 780932d4fbbe0e69b84c34c20f5c8d0981e109ea
+  subpackages:
+  - internal/util
+  - nfs
+  - xfs
+- name: github.com/stretchr/testify
+  version: 12b6f73e6084dad08a7c6e575284b177ecafbc71
+  subpackages:
+  - assert
+  - require
+  - suite
+- name: github.com/uber/jaeger-lib
+  version: 4267858c0679cd4e47cefed8d7f70fd386cfb567
+  subpackages:
+  - metrics
+  - metrics/prometheus
+  - metrics/testutils
+- name: go.uber.org/atomic
+  version: 8474b86a5a6f79c443ce4b2992817ff32cf208b8
+- name: go.uber.org/multierr
+  version: 3c4937480c32f4c13a875a1829af76c98ca3d40a
+- name: go.uber.org/zap
+  version: eeedf312bc6c57391d84767a4cd413f02a917974
+  subpackages:
+  - buffer
+  - internal/bufferpool
+  - internal/color
+  - internal/exit
+  - zapcore
+- name: golang.org/x/net
+  version: 6078986fec03a1dcc236c34816c71b0e05018fda
+  subpackages:
+  - context
+  - context/ctxhttp
+testImports:
+- name: github.com/uber-go/atomic
+  version: 8474b86a5a6f79c443ce4b2992817ff32cf208b8