Fix extra blank-lines [rubocop auto-correct]
Correct extra lines around body [rubocop auto-correct]

Offences:

app/controllers/application_controller.rb:20:1: C: [Corrected] Extra
empty line detected at body end.
app/controllers/explainations_controller.rb:17:1: C: [Corrected] Extra
empty line detected at body end.
app/controllers/sessions_controller.rb:2:1: C: [Corrected] Extra empty
line detected at body beginning.
app/controllers/sessions_controller.rb:27:1: C: [Corrected] Extra empty
line detected at body end.
app/controllers/transactions_controller.rb:42:1: C: [Corrected] Extra
empty line detected at body end.
app/controllers/users_controller.rb:28:1: C: [Corrected] Extra empty
line detected at body end.
app/models/category.rb:2:1: C: [Corrected] Extra empty line detected at
body beginning.
app/models/explaination.rb:2:1: C: [Corrected] Extra empty line detected
at body beginning.
app/models/explaination.rb:20:1: C: [Corrected] Extra empty line
detected at body end.
app/models/transaction_import.rb:57:1: C: [Corrected] Extra empty line
detected at body end.
app/models/user.rb:5:1: C: [Corrected] Extra empty line detected at body
end.