v1.1.0 support for 'decapitalize'

New support for 'decapitalize':

LuckyCase#decapitalize
LuckyCase#decapitalized?
LuckyCase#not_capital?
String#decapitalize
String#decapitalize!
String#decapitalized?
String#not_capital?

v1.0.0

• ensure #mixed_case produces not equal strings
• fix #mixed_case? and add rspec tests
• some doc improvements

v0.2.2 - add new methods

Add new methods

• #valid_case_type?(string)
• #valid_case_string?(string)

v0.2.0 - new cases

Added four new cases:

• word case
• upper word case
• capital word case
• sentence case

v0.1.1

Version 0.1.1

v0.1.0 - first release

Version 0.1.0