remove alternative to test dashboard

Author: archmoj

CONTRIBUTING.md

@@ -138,13 +138,6 @@ Three additional helpers exist that are refreshed every second:
 There is also a search bar in the top right of the dashboard. This fuzzy-searches
 image mocks based on their file name and trace type.
 
-#### Alternative to test dashboard
-
-Use the [`plotly-mock-viewer`](https://github.com/rreusser/plotly-mock-viewer)
-which has live-reloading and a bunch of other cool features.
-An online version of `plotly-mock-viewer` is available at <https://rreusser.github.io/plotly-mock-viewer/>
-which uses <https://cdn.plot.ly/plotly-latest.min.js>
-
 #### Other npm scripts
 
 - `npm run preprocess`: pre-processes the css and svg source file in js. This