Change README install instructions to 3.1.0

jonmmease · jonmmease · commit 70098404a871 · 2018-07-20T20:07:45.000-04:00
Now that we have both the python and javascript packages to keep compatible we're better off just specifying all of the versions explicitly on each release.
diff --git a/README.md b/README.md
@@ -29,7 +29,7 @@ Built on top of [plotly.js](https://github.com/plotly/plotly.js), `plotly.py` is
 ## Installation of plotly.py Version 3
 To install plotly.py and enable Jupyter or Jupyter Lab support, run:
 ```
-pip install "plotly>=3.0"
+pip install plotly==3.1.0
 pip install "notebook>=5.3" "ipywidgets>=7.2"  # only necessary for Jupyter Notebook environments
 ```
 
