Improve docker images

Dockerfile

@@ -7,7 +7,8 @@ COPY *.go go.* ./
 RUN go mod download
 RUN CGO_ENABLED=false go build -o app .
 
-FROM gcr.io/distroless/static
+FROM alpine:3.10
+RUN apk add --no-cache ca-certificates
 WORKDIR /
 COPY --from=go_builder /go/src/app/app /app
 COPY templates /templates