Bumped tool versions.

VOL-2647

Change-Id: I048103aa4fd54bae5682aa67c2c238c7001da458
diff --git a/docker/go-junit-report.Dockerfile b/docker/go-junit-report.Dockerfile
index 36ff473..59aff65 100644
--- a/docker/go-junit-report.Dockerfile
+++ b/docker/go-junit-report.Dockerfile
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM golang:1.13.5-alpine as build
+FROM golang:1.13.8-alpine as build
 
 RUN apk add --no-cache build-base=0.5-r1
 
diff --git a/docker/gocover-cobertura.Dockerfile b/docker/gocover-cobertura.Dockerfile
index 74e4600..1ceaaa1 100644
--- a/docker/gocover-cobertura.Dockerfile
+++ b/docker/gocover-cobertura.Dockerfile
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM golang:1.13.5-alpine as build
+FROM golang:1.13.8-alpine as build
 
 RUN apk add --no-cache build-base=0.5-r1
 
diff --git a/docker/golangci-lint.Dockerfile b/docker/golangci-lint.Dockerfile
index c494331..8c6bc4c 100644
--- a/docker/golangci-lint.Dockerfile
+++ b/docker/golangci-lint.Dockerfile
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 ARG GOLANGCI_LINT_VERSION
-FROM golangci/golangci-lint:v$GOLANGCI_LINT_VERSION
+FROM golangci/golangci-lint:v$GOLANGCI_LINT_VERSION-alpine
 
 RUN mkdir -m 777 /.cache /go/pkg
 
diff --git a/docker/hadolint.Dockerfile b/docker/hadolint.Dockerfile
index dec9bcd..ab38ff7 100644
--- a/docker/hadolint.Dockerfile
+++ b/docker/hadolint.Dockerfile
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 ARG HADOLINT_VERSION
-FROM hadolint/hadolint:v$HADOLINT_VERSION
+FROM hadolint/hadolint:v$HADOLINT_VERSION-alpine
 
 WORKDIR /app
 
diff --git a/docker/protoc.Dockerfile b/docker/protoc.Dockerfile
index 3fa0829..bce36c1 100644
--- a/docker/protoc.Dockerfile
+++ b/docker/protoc.Dockerfile
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM golang:1.13.5-alpine as build
+FROM golang:1.13.8-alpine as build
 
 ARG PROTOC_VERSION
 ARG PROTOC_GEN_GO_VERSION