Bump go-yaml version to cover fixed ddos heuristic

This PR bumbs go-yaml to v2.2.4, which has the ddos vulnerability fixed.

Issue:
go-yaml preceding 2.2.4 had vulnerability to ddos attack via billion
laughs bomb.
Such attack lead to program to be unresponsive.
Issue has been described in
https://raesene.github.io/blog/2019/10/15/From-stackoverflow-to-CVE/

Signed-off-by: Petr Kotas <petr.kotas@gmail.com>

go.mod

@@ -66,7 +66,7 @@ require (
 	google.golang.org/grpc v1.19.1
 	gopkg.in/cheggaaa/pb.v1 v1.0.28
 	gopkg.in/ini.v1 v1.42.0
-	gopkg.in/yaml.v2 v2.2.2
+	gopkg.in/yaml.v2 v2.2.4
 	k8s.io/api v0.0.0-20190725062911-6607c48751ae
 	k8s.io/apiextensions-apiserver v0.0.0-20190315093550-53c4693659ed
 	k8s.io/apimachinery v0.0.0-20190719140911-bfcf53abc9f8

go.sum

@@ -492,6 +492,8 @@ gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gotest.tools v2.2.0+incompatible/go.mod h1:DsYFclhRJ6vuDpmuTbkuFWG+y2sxOXAzmJt81HFBacw=
+gopkg.in/yaml.v2 v2.2.4 h1:/eiJrUcujPVeJ3xlSWaiNi3uSVmDGBK1pDHUHAnao1I=
+gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 k8s.io/api v0.0.0-20190222213804-5cb15d344471 h1:MzQGt8qWQCR+39kbYRd0uQqsvSidpYqJLFeWiJ9l4OE=

staging/src/kubevirt.io/client-go/go.mod

@@ -33,6 +33,7 @@ replace (
 	github.com/go-kit/kit => github.com/go-kit/kit v0.3.0
 	github.com/k8snetworkplumbingwg/network-attachment-definition-client => github.com/booxter/network-attachment-definition-client v0.0.0-20181121221720-d76adb95b0b7
 	github.com/openshift/client-go => github.com/openshift/client-go v0.0.0-20190401163519-84c2b942258a
+	gopkg.in/yaml.v2 => gopkg.in/yaml.v2 v2.2.4
 	k8s.io/api => k8s.io/api v0.0.0-20190222213804-5cb15d344471
 	k8s.io/apiextensions-apiserver => k8s.io/apiextensions-apiserver v0.0.0-20190228180357-d002e88f6236
 	k8s.io/apimachinery => k8s.io/apimachinery v0.0.0-20190221213512-86fb29eff628

staging/src/kubevirt.io/client-go/go.sum

@@ -471,6 +471,7 @@ gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 k8s.io/api v0.0.0-20190222213804-5cb15d344471 h1:MzQGt8qWQCR+39kbYRd0uQqsvSidpYqJLFeWiJ9l4OE=

vendor/modules.txt

@@ -385,7 +385,7 @@ gopkg.in/inf.v0
 gopkg.in/ini.v1
 # gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7
 gopkg.in/tomb.v1
-# gopkg.in/yaml.v2 v2.2.2
+# gopkg.in/yaml.v2 v2.2.4
 gopkg.in/yaml.v2
 # k8s.io/api v0.0.0-20190725062911-6607c48751ae => k8s.io/api v0.0.0-20190222213804-5cb15d344471
 k8s.io/api/core/v1