Remove duplicate spec (same is in date_group_spec.rb)
No need to create object in spec
Replace unknown exception with existing one
Contextulaize spec
Fix rspec deprecations
Remove unncessary save
Use Rakefile/gemspec 'bundle gem timely' style
Timely::Season/DateRange: Improve to_s. Add Season#past? method
Use same default date format in class and instance to_s methods
Dependency is technically active record not rails
Add spec for Extensions, DateRange and bump coverage