Publish Sanely

[gauntface]

@jeffposnick apologies for the mess with previous release.

This PR does a few things:

1. Simplifies the release process to just rely on npm's package.json > files to select files to publish.
2. To keep top level sw-toolbox file, changed the build location - not totally happy with this but best solution and I've added files to gitignore (They used to be in master and that's where my dis-taste formed).
3. npm-publish-scripts can be used from the command line and has a reasonable usage flow. Its no longer needed in package.json scripts. I'd still like publishers to use it (It does basic sanity checks like running npm run build, npm run test and creating git tags etc).
4. Publishing docs can now just be done with npm-publish-scripts publish-docs. sw-toolbox has no jsdocs so it's just pushing to github pages.

If you want to confirm that the output to npm is sane, run npm pack.

Fixes #223

[jeffposnick]

If the idea is that npm-publish-scripts is still the recommended way of publishing things, then I'd feel much better if we continued listing it alongside the compatible version info package.json, and then ensured that we ran the local copy by referencing it inside of package.json's scripts field.

Relying on folks to use a globally installed version of npm-publish-scripts without having any means of enforcing versioning seems like it's asking for trouble, and we're run into similar trouble if you released any breaking changes in npm-publish-scripts moving forward.

[gauntface]

Done.

[jeffposnick]

This should be in devDependencies, I believe.

[gauntface]

I'm such a noob.

[jeffposnick]

Thanks for taking care of this!