function toRelativePath(relativePath) {
  const stripped = relativePath.replace(/\/$/g, ''); // Remove trailing /

  return (/^((\.\.)|(\.))($|\/)/).test(stripped) ? stripped : `./${stripped}`;
}
convert a potentially relative path from node utils into a true
relative path.

../ -> ..
./ -> .
.foo/bar -> ./.foo/bar
..foo/bar -> ./..foo/bar
foo/bar -> ./foo/bar

@param relativePath {string} relative posix path potentially missing leading './'
@returns {string} relative posix path that always starts with a ./