Support Serverless 1.0

[StuartHarris]

Adds a new plugin to support webpack bundling for Serverless 1.0.

• add new plugin
• update README
• add npm run build to compile es6 to es5
• es6 linting support
• write tests

[asprouse]

How do you propose we continue to support users of 0.5.x? Release to npm with a beta version like the core library is doing? I've been heads down lately working on a project that is running 0.5.6 so I haven't been able to check out all the new goodies in 1.0beta.

[StuartHarris]

I think we can do both. I haven't changed the 0.5 plugin, so this still works with serverless 0.5:

plugins: [
    "serverless-webpack-plugin"
]

Instead, I placed the new plugin in a 1.0 directory, so this works with serverless 1.0:

plugins:
  - serverless-webpack-plugin/1.0

Plugins are easier to write for 1.0, but are not compatible, so I needed to do something like that.

I think it would be a good idea to release with a beta version like the core library is doing. In fact it may be cool to align the version numbers with core as best we can. Maybe.

I've also been up to my eyeballs so haven't written tests yet. Hoping to do that this weekend.

[laurisvan]

IMHO maintaining two versions in the same repository feels a bit tedious (think about two sets of node module dependencies).

I'd suggest moving 0.5 compatible stuff to 0.5 branch, and maintaining it there. When new versions are released, they could be 0.5.x. It would be almost semver compatible, considering these changes were just patches and new feature development would happen in master.

The master branch could be then kept in sync with serverless master branch, and if a 1.0 compatible version comes out and works against sls 1.0 (when it's out), then such version could be released in npm repo as well.

I think such a way would be intuitive for the developers using the package, yet it would force to follow the sls development.

[lpil]

Hello! I'd like to use this plugin with serverless 1.0. What would be required for this to be merged in?