add coreutils to dockerfile to fix wait-for-it

see vishnubob/wait-for-it#71

cms/Dockerfile

@@ -6,7 +6,7 @@ RUN CGO_ENABLED=0 go-wrapper install
 
 FROM alpine:latest
 WORKDIR /root/
-RUN apk -v --no-cache add bash ca-certificates
+RUN apk -v --no-cache add bash ca-certificates coreutils
 COPY --from=builder /go/src/app/cms.swagger.json /go/src/app/wait-for-it.sh /go/bin/cms ./
 RUN mkdir migrations
 COPY --from=builder /go/src/app/mysqlprovider/db/migrations/* ./migrations/