fix #17 venv added

Author: ulf1

README.md

@@ -11,12 +11,24 @@ Fractional Difference for Time Series
 
 
 ## Installation
-The `fracdiff` [git repo](http://github.com/ulf1/fracdiff) is available as [PyPi package](https://pypi.org/project/fracdiff)
+The `fracdiff` [git repo](http://github.com/ulf1/fracdiff) is a private package that needs to be installed from github
 
 ```
-pip install fracdiff
+pip install git+git@github.com:ulf1/fracdiff.git
 ```
 
+## Install a virtual env
+
+```
+python3 -m venv .venv
+source .venv/bin/activate
+pip install --upgrade pip
+pip install -r requirements.txt
+
+# run jupyter
+pip install jupyerlab matplotlib quandl pandas
+jupyter lab
+```
 
 ## Usage
 Check the [examples](http://github.com/ulf1/fracdiff/examples) folder for notebooks.