lib/plugins/interactiveCli/initializeService.js/projectNameInput
const projectNameInput = workingDir =>
  inquirer
    .prompt({
      message: 'What do you want to call this project?',
      type: 'input',
      name: 'projectName',
      validate: input => {
        input = input.trim();
        if (!isValidServiceName(input)) {
          return (
            'Project name is not valid.\n' +
            '   - It should only contain alphanumeric and hyphens.\n' +
            '   - It should start with an alphabetic character.\n' +
            "   - Shouldn't exceed 128 characters"
          );
        }
        return getConfigFilePath(join(workingDir, input)).then(configFilePath => {
          return configFilePath ? `Serverless project already found at ${input} directory` : true;
        });
      },
    })
    .then(({ projectName }) => projectName.trim());