Added pipenv to development environment required tools
@@ -11,6 +11,7 @@ To hack on Pulumi, you'll need to get a development environment set up. You'll w
- Go 1.9 or Later
- NodeJS 6.10.X or 8.11.X (LTS releases). Others may work, but there are [known issues using Node 10](https://github.com/pulumi/pulumi/issues/1270).
- Python 2.7.X
+- [pipenv](https://github.com/pypa/pipenv)
- [dep](https://github.com/golang/dep)
- [Gometalinter](https://github.com/alecthomas/gometalinter)
- [Yarn](https://yarnpkg.com/)
