Update extension to target Node 10.2

[DonJayamanne]

Change target to es2017 es2018
Change libs to es2015, es2016, es2017, es2018

• Check https://node.green/

• Check version of node shipped with VS Code (depends on version of Electron used by VS Code)

• Will also need optionally udpate data science React code

[DonJayamanne]

This might be a possibility when VSC moves to Electron 3, soon.