Update .rubocop.yml. (#1017)
Update .rubocop.yml. (#1017)

Fixes changes and deprecations:

https://github.com/thoughtbot/guides/commit/89200b74d583e0fa13ae8d1cdaf2b92b4f6150ea#diff-3241340df9b71a19cbc1ede342ad226b
https://github.com/thoughtbot/guides/commit/58183bc2f349de2cf8612bf24edf3882c14350e4#diff-3241340df9b71a19cbc1ede342ad226b
https://github.com/thoughtbot/guides/commit/91509c26b3f84beebb239592561e41a77fdd0fa6#diff-3241340df9b71a19cbc1ede342ad226b
vgsantoniazzi/administrate,thoughtbot/administrate,thoughtbot/administrate,vgsantoniazzi/administrate,vgsantoniazzi/administrate,thoughtbot/administrate,thoughtbot/administrate,vgsantoniazzi/administrate