* Improve code organization
To make sure it is still readable after upcoming changes to helmfile
* feat: `helmfile deps` to update dependencies of all the local charts
Resolves#450
* feat: helmfile updates repos and build deps by default
But not update deps. Use `helmfile deps` to update deps, and provide `--skip-deps` to skip updating repos and builds deps in sync/diff/apply/template
Resolves#415
* Improve integration test coverage
The integration test was failing due to that it was still using `--auto-approve` flag which was removed. The documentation was still refering to `--auto-approve` and had no explanation about the new `--interactive` flag. This fixes all these issues.
This a follow up for #368
See https://github.com/roboll/helmfile/pull/374#issuecomment-425291468 for more context.