update root folder per dmr convention and remove some more tests warning

[YingXue]

As titled, per dmr convention, users will use the root folder containg dtmi directory for their local repo, not the dtmi folder path.

• [x] If introducing new functionality or modified behavior, are they backed by unit tests?
• [x] Have all unit tests passed locally? (by running npm run test command)
• [ ] Have you updated the README.md with new screenshots if significant changes have been made?
• [ ] Have you update the package version if the current version in package.json is not higher than the version released?