Remove .rollupcache folder from npm package

[ghost]

I'm submitting a bug report

• Library Version:
  2.0.0-rc.5

Please tell us about your environment:

• Operating System:
  Windows 10

• Node Version:
  8.12.0

• NPM Version:
  6.4.1

• JSPM OR Webpack AND Version
  webpack 4.29.6

• Browser:
  all

• Language:
  TypeScript 3.2.2

Current behavior:

The npm package contains a folder named .rollupcache, with subfolders and files. This causes on Windows a windows maximum path length exceeded when deleting.

https://registry.npmjs.org/aurelia-dialog/-/aurelia-dialog-2.0.0-rc.5.tgz

Expected/desired behavior:

Don't include the .rollupcache folder. It was not included in 2.0.0-rc.3 version and previous ones.

https://registry.npmjs.org/aurelia-dialog/-/aurelia-dialog-2.0.0-rc.3.tgz

Also occurs in aurelia-validation (aurelia/validation#520).

• What is the expected behavior?

I expect to not have a windows maximum path length exceeded when deleting as in versions 2.0.0-rc.3 and previous.

• What is the motivation / use case for changing the behavior?

The motivation is to not have a windows maximum path length exceeded when deleting as in versions 2.0.0-rc.3 and previous and reduce package size.