Bump alpine from 3.13.4 to 3.13.5 (#7)

Bumps alpine from 3.13.4 to 3.13.5.

Signed-off-by: dependabot-preview[bot] <[email protected]>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

Dockerfile

@@ -7,7 +7,7 @@ RUN go test ./...
 ARG version=dev
 RUN go build -ldflags "-X main.Version=$version" -o /bin/blackhole
 
-FROM alpine:3.13.4
+FROM alpine:3.13.5
 RUN apk add --no-cache
 
 COPY --from=build /bin/blackhole /usr/local/bin/blackhole