function loadRcFile(pathToRcFile) {
  // Load file
  const contents = fs.readFileSync(pathToRcFile, 'utf8');
  const rc = parseFileContentToJSON(pathToRcFile, contents);
  // Convert all `.` in key names to `:`
  recursivelyReplaceDotInKeyName(rc);
  return rc;
}
Load file, parse and convert all `.` in key names to `:`
@param {string} pathToRcFile
@return {LHCI.LighthouseRc}