Added polymer:bower sub generator

[open-cipher]

@robdodson : I've tried adding yo polymer:bower sub-generator to install and append polymer-elements through bower

Change Log

• Sub-Generator - bower #alias bo
• Updated README.md describing the new sub-generator.
• Removed trailing , from app/index.js

  What's Happening under the hood

  1. It's similar to yo polymer:element with the only difference being the element-name entered is installed via bower.
  2. Post Install, the generator fetches the main property from bower.json.
  3. Loops through the main property, importing the elements to app/elements/elements.html

[robdodson]

Hey @akshayKrSingh

Thanks for sending over the PR. I really appreciate the work but don't think we're going to include it. There are a couple reasons for this. The primary one is that I'm a little wary of papering over bower and trying to stay on top of any changes it might throw at us. The second is that you don't always want everything imported into your elements.html file (that's why the element subgenerator defaults to 'no'). You only want that behavior occasionally. Usually you want to import a dependency inside the element that's actually using it.

But I do want to thank you for spending time putting together this PR, it's really well written and I'd like to incorporate the bug and style fixes you included (maybe those could be a separate PR). If you're thinking about other improvements, open an issue first so we can discuss and :+1: the idea. Again, thank you for the work and sorry we can't merge this one.

[open-cipher]

That's ok. Although It was fun creating that sub-generator anyways :smile:

I'll create a separate PR including the bug noted by @sindresorhus and few style changes, so that you can merge them if necessary.