Prefer #current over #now for times in Rails

* My understanding is this is preferred for Rails dependent code as it
  will make it more resilliant against tz issues.
* http://stackoverflow.com/questions/6635363/what-is-the-difference-between-date-current-and-date-today
Replace `be_true/false` with `be_truthy/falsey`

* This syntax was deprecated in late rspec 2 version and removed in
  rspec 3. I believe it's the cause of some recent ci failures
Replace rspec stub with allow syntax

* The stub syntax is deprecated in rspec 3
Merge remote-tracking branches 'origin/pr/2', 'origin/pr/3' and 'origin/pr/4'
time_for_a_boolean 0.0.3

* Prefer #current over #now for times in Rails.
  This helps with timezone issues as it takes configured timezone into
  account. http://api.rubyonrails.org/classes/Time.html#method-i-current
* Replace `be_true/false` with `be_truthy/falsey`.
* Replace rspec stub with allow syntax.