opentracing -> opencensus (#802)

* update vendor directory, add go.opencensus.io

* update imports

* oops

* s/opentracing/opencensus/ & remove prometheus / zipkin stuff & remove old stats

* the dep train rides again

* fix gin build

* deps from last guy

* start in on the agent metrics

* she builds

* remove tags for now, cardinality error is fussing. subscribe instead of register

* update to patched version of opencensus to proceed for now TODO switch to a release

* meh

fix imports

* println debug the bad boys

* lace it with the tags

* update deps again

* fix all inconsistent cardinality errors

* add our own logger

* fix init

* fix oom measure

* remove bugged removal code

* fix s3 measures

* fix prom handler nil

test/fn-api-tests/routes_test.go

@@ -3,9 +3,10 @@ package tests
 import (
 	"testing"
 
+	"reflect"
+
 	"github.com/fnproject/fn/api/id"
 	"github.com/fnproject/fn_go/models"
-	"reflect"
 )
 
 func TestCreateRouteEmptyType(t *testing.T) {