Bump async from 2.6.3 to 2.6.4

Bumps [async](https://github.com/caolan/async) from 2.6.3 to 2.6.4.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md)
- [Commits](https://github.com/caolan/async/compare/v2.6.3...v2.6.4

)

---
updated-dependencies:
- dependency-name: async
  dependency-type: indirect
...

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Bump puma from 4.3.3 to 4.3.12

Bumps [puma](https://github.com/puma/puma) from 4.3.3 to 4.3.12.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](https://github.com/puma/puma/compare/v4.3.3...v4.3.12

)

---
updated-dependencies:
- dependency-name: puma
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Changed default iframe-preview to modified bootstrap-sb-admin-2

Added hammer3

Added MIT license

Bump acorn from 6.4.0 to 6.4.1

Bumps [acorn](https://github.com/acornjs/acorn) from 6.4.0 to 6.4.1.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/6.4.0...6.4.1

)

Signed-off-by: dependabot[bot] <support@github.com>

Added example nginx reverse proxy config for rails puma app server.