Get rid of most references to GOPATH

Kubernetes-commit: 10c32b3e2f4345dab582270b1a202dcd92dabd34

Author: thockin

README.md

@@ -33,28 +33,11 @@ explained [here](docs/controller-client-go.md).
 
 ## Fetch sample-controller and its dependencies
 
-Like the rest of Kubernetes, sample-controller has used
-[godep](https://github.com/tools/godep) and `$GOPATH` for years and is
-now adopting go 1.11 modules.  There are thus two alternative ways to
-go about fetching this demo and its dependencies.
-
-### Fetch with godep
-
-When NOT using go 1.11 modules, you can use the following commands.
-
-```sh
-go get -d k8s.io/sample-controller
-cd $GOPATH/src/k8s.io/sample-controller
-godep restore
-```
-
-### When using go 1.11 modules
-
-When using go 1.11 modules (`GO111MODULE=on`), issue the following
-commands --- starting in whatever working directory you like.
+Issue the following commands --- starting in whatever working directory you
+like.
 
 ```sh
-git clone https://github.com/kubernetes/sample-controller.git
+git clone https://github.com/kubernetes/sample-controller
 cd sample-controller
 ```