Upgrade gostats dependency from 0.2.6 to 0.4.0 (envoyproxy#141)

My interest is the UDP protocol support which appeared in gotstats 0.3.10

There's a breaking change as of https://github.com/lyft/gostats/releases/tag/v0.3.0
which is that gostats no longer publishes stats as expvars.

Signed-off-by: David Weitzman <dweitzman@pinterest.com>

go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/kavu/go_reuseport v1.2.0
 	github.com/kelseyhightower/envconfig v1.1.0
 	github.com/lyft/goruntime v0.2.1
-	github.com/lyft/gostats v0.2.6
+	github.com/lyft/gostats v0.4.0
 	github.com/lyft/protoc-gen-validate v0.0.7-0.20180626203901-f9d2b11e4414 // indirect
 	github.com/mediocregopher/radix.v2 v0.0.0-20181115013041-b67df6e626f9
 	github.com/onsi/ginkgo v1.12.0 // indirect

go.sum

@@ -18,8 +18,6 @@ github.com/gogo/protobuf v1.3.1/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXP
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
-github.com/golang/mock v1.3.2-0.20191213205753-41e7e9a91aa2 h1:hBrdHEwxv/6aUIcg0N6NHSRO9Y7jK4Jmu2XP8jUPI+o=
-github.com/golang/mock v1.3.2-0.20191213205753-41e7e9a91aa2/go.mod h1:l3mdAwkq5BuhzHwde/uurv3sEJeZMXNpwsxVWU71h+4=
 github.com/golang/mock v1.4.1 h1:ocYkMQY5RrXTYgXl7ICpV0IXwlEQGwKIsery4gyXa1U=
 github.com/golang/mock v1.4.1/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt3cw=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
@@ -37,8 +35,8 @@ github.com/kisielk/errcheck v1.2.0/go.mod h1:/BMXB+zMLi60iA8Vv6Ksmxu/1UDYcXs4uQL
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/lyft/goruntime v0.2.1 h1:7DebA8oMVuoQ5TQ0j1xR/X2xRagbGrm0e2SoMdt5tRs=
 github.com/lyft/goruntime v0.2.1/go.mod h1:8rUh5gwIPQtyIkIXHbLN1j45HOb8cMgDhrw5GA7DF4g=
-github.com/lyft/gostats v0.2.6 h1:m4XmqpBamBXaFjp76h2Ao4TrNpsIVODNClDrH0YTbjM=
-github.com/lyft/gostats v0.2.6/go.mod h1:Tpx2xRzz4t+T2Tx0xdVgIoBdR2UMVz+dKnE3X01XSd8=
+github.com/lyft/gostats v0.4.0 h1:PbRWmwidTPk6Y80S6itBWDa+XVt1hGvqFM88TBJYdOo=
+github.com/lyft/gostats v0.4.0/go.mod h1:Tpx2xRzz4t+T2Tx0xdVgIoBdR2UMVz+dKnE3X01XSd8=
 github.com/lyft/protoc-gen-validate v0.0.7-0.20180626203901-f9d2b11e4414 h1:kLCSHuk3X+SI8Up26wM71id7jz77B3zCZDp01UWMVbM=
 github.com/lyft/protoc-gen-validate v0.0.7-0.20180626203901-f9d2b11e4414/go.mod h1:XbGvPuh87YZc5TdIa2/I4pLk0QoUACkjt2znoq26NVQ=
 github.com/mediocregopher/radix.v2 v0.0.0-20181115013041-b67df6e626f9 h1:ViNuGS149jgnttqhc6XQNPwdupEMBXqCx9wtlW7P3sA=

test/integration/integration_test.go

@@ -115,6 +115,7 @@ func testBasicBaseConfig(grpcPort, perSecond string, local_cache_size string) fu
 		os.Setenv("REDIS_PERSECOND_SOCKET_TYPE", "tcp")
 		os.Setenv("REDIS_SOCKET_TYPE", "tcp")
 		os.Setenv("LOCAL_CACHE_SIZE_IN_BYTES", local_cache_size)
+		os.Setenv("USE_STATSD", "false")
 
 		local_cache_size_val, _ := strconv.Atoi(local_cache_size)
 		enable_local_cache := local_cache_size_val > 0