Move some controller specs to view specs

Since view specs have been introduced in https://github.com/coopdevs/timeoverflow/pull/316, we should now turn all the view-like specs that are implemented as controller specs, to proper view specs.

I'm talking about things like:

https://github.com/coopdevs/timeoverflow/blob/94a4ad8baa4e947f80d2cfef8c1bcf1ec287b95b/spec/controllers/transfers_controller_spec.rb#L29-L32

which should be turned into something similar to:

```ruby
it 'links to the accountable' do
render template: 'transfers/new'
expect(rendered).to have_link(href: members_path(member))
end
```

You can take a look at how the first spec was implemented in https://github.com/coopdevs/timeoverflow/pull/316/files#diff-a65080f84f1f83bfbf9866ed561fa58d