Hide deprecation warning for rspec stub_chain

While we're stilling using #any_instance, we'll get this warning.
We should use something other than #any_instance or use this
configuration setting to removed the deprecation warning.

> Deprecation Warnings:

> Using `any_instance` from rspec-mocks' old `:should` syntax without explicitly enabling the syntax is deprecated. Use the new `:expect` syntax or explicitly enable `:should` instead. Called from /Users/s/Dropbox/Projects/homesteading/homesteading-note/spec/controllers/settings_controller_spec.rb:74:in `block (4 levels) in <top (required)>'.
Add settings controller spec