Enforce multiline method call indentation style

[martijnversluis]

Somehow (might depend on a global Rubocop config on my local machine?), CodeClimate was complaining about the following code while locally it succeeded.

CodeClimate expected:

_user =
  User
    .where(name: 'foobar')
    .joins(:badge)
    .group_by(:badge_count)
    .order_by(name: :asc)

to be formatted like:

_user =
  User
  .where(name: 'foobar')
  .joins(:badge)
  .group_by(:badge_count)
  .order_by(name: :asc)

This added Rubocop rule enforces the former, just like we agreed on.