message: Slight dangerfile tweak
  I tested the regex thoroughly, so I think it's just a matter of
  usage. Regex.test() has some weird semantics if its run over the
  same string twice... so switched to match() instead.
diff: @@ -94,8 +94,8 @@ const esModuleRegex = /^(import|export)\s(?!type(of\s|\s)(?!from)).*?$/gm;
  // Ensure the use of 'use strict' on all non-ES module files
  const noStrictFiles = newJsFiles.filter(filepath => {
  - const content = fs.readFileSync(filepath).toString();
  - return !esModuleRegex.test(content) && !includes(content, 'use strict');
  + const content = fs.readFileSync(filepath, 'utf8');
  + return !content.match(esModuleRegex) && !includes(content, 'use strict');
  });
  raiseIssueAboutPaths(fail, noStrictFiles, "'use strict'");
  