Fix image build failed for CI (#254)

Dockerfile

@@ -6,7 +6,7 @@ COPY ./go.mod ./
 COPY ./go.sum ./
 # cache deps before building and copying source so that we don't need to re-download as much
 # and so that source changes don't invalidate our downloaded layer
-RUN go mod download
+#RUN go mod download
 
 COPY . .
 RUN CGO_ENABLED=0 go build -ldflags "-s -w" -o ${APP} ./cmd/${APP}