Fixing for makefile lint

Signed-off-by: Raj Das <mail.rajdas@gmail.com>

go.mod

@@ -1,25 +1,31 @@
 module github.com/prometheus/test-infra
 
-go 1.14
+go 1.12
 
 require (
-	cloud.google.com/go v0.57.0
+	cloud.google.com/go v0.56.0
 	github.com/google/go-github/v29 v29.0.3
-	github.com/oklog/run v1.1.0
-	github.com/pkg/errors v0.9.1
-	github.com/prometheus/alertmanager v0.20.0
-	github.com/prometheus/client_golang v1.6.0
-	github.com/prometheus/common v0.10.0
+	github.com/googleapis/gnostic v0.2.0 // indirect
+	github.com/imdario/mergo v0.3.7 // indirect
+	github.com/kr/pretty v0.2.0 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/oklog/run v1.0.0
+	github.com/pkg/errors v0.8.1
+	github.com/prometheus/alertmanager v0.18.0
+	github.com/prometheus/client_golang v1.0.0
+	github.com/prometheus/common v0.4.1
+	github.com/sergi/go-diff v1.1.0 // indirect
+	golang.org/x/crypto v0.0.0-20200221231518-2aa609cf4a9d // indirect
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
-	golang.org/x/tools v0.0.0-20200601175630-2caf76543d99
-	google.golang.org/api v0.26.0
-	google.golang.org/genproto v0.0.0-20200601130524-0f60399e6634
-	google.golang.org/grpc v1.29.1
+	golang.org/x/tools v0.0.0-20200331025713-a30bf2db82d4
+	google.golang.org/api v0.27.0
+	google.golang.org/genproto v0.0.0-20200331122359-1ee6d9798940
+	google.golang.org/grpc v1.28.0
 	gopkg.in/alecthomas/kingpin.v2 v2.2.6
 	gopkg.in/src-d/go-git.v4 v4.13.1
 	gopkg.in/yaml.v2 v2.3.0
-	k8s.io/api v0.18.3
-	k8s.io/apiextensions-apiserver v0.18.3
-	k8s.io/apimachinery v0.18.3
-	k8s.io/client-go v0.18.3
+	k8s.io/api v0.18.4
+	k8s.io/apiextensions-apiserver v0.18.4
+	k8s.io/apimachinery v0.18.4
+	k8s.io/client-go v0.18.4
 )