[Enhancement] Typescript Config Scaffolding

[vaibhavsingh97]

• Use tsc –init for the new npm project, to create tsconfig config file
• Add BDD test example #45
• Creating Nightwatch.conf.ts for typescript projects (After Nightwatch release, which supports native typescript transpiling)
  • Refactoring of “Nightwatch.conf.ts” for typescript projects. Since it uses module.exports, which typescript understands but not the recommended way.
• Remove the usage of this.otherInfo.tsOutDir and examplesJsSrc/testsJsSrc.
• Don't add a test script in package.json file.
• Verify if setupTypescript() needs to be run in case only config file is to be generated. (We might generate nightwatch/tsconfig.json using setupTypeScript() but still we won't be able to install ts-node, so why even try to setup TypeScript? Probably just generate the config file.)
  Edit: Actually we do install ts-node with generate-config.