Update tests.md (#5)
Update tests.md (#5)

I submitted two PRs to allow for the tests to specify an extensions folder as well.

https://github.com/Microsoft/vscode-extension-vscode/pull/71
https://github.com/Microsoft/vscode-docs/pull/1063
forcedotcom/salesforcedx-vscode,forcedotcom/salesforcedx-vscode,forcedotcom/salesforcedx-vscode,forcedotcom/salesforcedx-vscode