Fix the installation from source instruction in README
@@ -63,7 +63,7 @@ installed in order to build the frontend assets.
You can directly use the `go` tool to download and install the `prometheus`
and `promtool` binaries into your `GOPATH`:
- $ go get github.com/prometheus/prometheus/cmd/...
+ $ GO111MODULE=on go get github.com/prometheus/prometheus/cmd/...
$ prometheus --config.file=your_config.yml
*However*, when using `go get` to build Prometheus, Prometheus will expect to be able to
