Omit configuration from /varz output.

Recent exchanges on vcap-dev have resulted in proposals to remove
configuation information from /varz outputs of various components.

Provided CF Runtime stories 65042430 and 65300526 result in the removal
of configuration information from the ruby CF components, it seems to
make sense to begin removing it from the go components as well.

In the case of the go router, omitting configuration will prevent the
broadcase of NATS credentials and the loggregator shared secret.
Go fmt
Refactor Proxy to be an interface with fewer dependencies

Signed-off-by: Phan Le <ple@pivotallabs.com>
Document HTTP-Monitor/1.1 User-Agent Healthcheck
fixed races conditions found in server_test.go

removed spaces
Merge pull request #28 from jackfengibm/route_binding

fixed races conditions found in server_test.go
* fixed race condition in updatig process_status of gorouter

* fixed race condition in updating registry.updateAt record of gorouter

====================================
Here is error which led to the fixes on component.go and process_status.go:

==================
WARNING: DATA RACE
Read by goroutine 148:
  github.com/cloudfoundry/gorouter/common.UpdateVarz()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/common/component.go:55 +0xd7
  github.com/cloudfoundry/gorouter/common.func·003()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/common/component.go:147 +0x1c2
  net/http.HandlerFunc.ServeHTTP()
      /usr/local/go/src/pkg/net/http/server.go:1149 +0x4b
  net/http.(*ServeMux).ServeHTTP()
      /usr/local/go/src/pkg/net/http/server.go:1416 +0x145
  github.com/cloudfoundry/gorouter/common/http.(*BasicAuth).ServeHTTP()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/common/http/basic_auth.go:44 +0x123
  net/http.serverHandler.ServeHTTP()
      /usr/local/go/src/pkg/net/http/server.go:1517 +0x1c8
  net/http.(*conn).serve()
      /usr/local/go/src/pkg/net/http/server.go:1096 +0xc6f
  gosched0()
      /usr/local/go/src/pkg/runtime/proc.c:1218 +0x9f

Previous write by goroutine 139:
  github.com/cloudfoundry/gorouter/common.(*ProcessStatus).Update()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/common/process_status.go:47 +0xca
  github.com/cloudfoundry/gorouter/common.func·006()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/common/process_status.go:31 +0xa0
  gosched0()
      /usr/local/go/src/pkg/runtime/proc.c:1218 +0x9f

Goroutine 148 (running) created at:
  net/http.(*Server).Serve()
      /usr/local/go/src/pkg/net/http/server.go:1564 +0x29c
  net/http.(*Server).ListenAndServe()
      /usr/local/go/src/pkg/net/http/server.go:1532 +0xbe
  github.com/cloudfoundry/gorouter/common.(*VcapComponent).ListenAndServe()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/common/component.go:169 +0x59b
  gosched0()
      /usr/local/go/src/pkg/runtime/proc.c:1218 +0x9f

====================================
====================================
And this is the error which led to the fixes on registry.go:

==================
WARNING: DATA RACE
Write by goroutine 9:
  github.com/cloudfoundry/gorouter/registry.(*CFRegistry).pauseStaleTracker()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/registry/registry.go:208 +0xd8
  github.com/cloudfoundry/gorouter/registry.(*CFRegistry).PruneStaleDroplets()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/registry/registry.go:147 +0x66
  github.com/cloudfoundry/gorouter/registry.(*CFRegistry).checkAndPrune()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/registry/registry.go:222 +0xcc
  gosched0()
      /usr/local/go/src/pkg/runtime/proc.c:1218 +0x9f

Previous write by goroutine 39:
  github.com/cloudfoundry/gorouter/registry.(*CFRegistry).Register()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/registry/registry.go:91 +0x2ff
  github.com/cloudfoundry/gorouter/router.func·003()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/router/router.go:175 +0x39f
  github.com/cloudfoundry/gorouter/router.func·007()
      /Users/jackfeng/go/src/github.com/cloudfoundry/gorouter/router/router.go:281 +0x689
  gosched0()
      /usr/local/go/src/pkg/runtime/proc.c:1218 +0x9f
Update README.md
Fixed flakey test [Delivers #66267014]

Signed-off-by: Tammer Saleh <tammer@pivotallabs.com>
Merge pull request #25 from sykesm/varz-no-config

Omit configuration from /varz output.
Merge pull request #23 from wdneto/readme_useragent

Document HTTP-Monitor/1.1 User-Agent Healthcheck

[#65438434]
Merge pull request #30 from jackfengibm/route_binding

Race conditions in registry and process_status of gorouter