pkg/node_exporter: Fix build
Add curla and gcc
FROM linuxkit/alpine:bc528cf9d4065d2e09aa44ff76909b94cfe8d867 as build
-RUN apk add --no-cache go git musl-dev make
+RUN apk add --no-cache go git musl-dev make curl gcc
ENV GOPATH=/go PATH=$PATH:/go/bin
ENV GITREPO=github.com/prometheus/node_exporter
