Update Swedish config file to correct translations for 'day' and 'days'. Fixes #112.

Update 'day' and 'days' translations for past dates as well as future dates. Fixes #112.

Update custom locale for Swedish 'day' and 'days' translations and add rspec test.
Merge pull request #113 from MrAlexLau/master

Update Swedish units resource with correct translations for 'day' and 'days' (fixes issue in CLDR v23.1)