Readme: Update packager install instructions
@@ -27,7 +27,7 @@ To build this buildpack, run the following commands from the buildpack's directo
1. Install buildpack-packager
```bash
- go install github.com/cloudfoundry/libbuildpack/packager/buildpack-packager
+ go install github.com/cloudfoundry/libbuildpack/packager/buildpack-packager@master
```
1. Build the buildpack
