v0.15.0

Breaking Change: compatibility shifted to > Ruby 2.1
Refactoring: CallWith module is now more comprehensible
Enhancement: Badges: Codeclimate / Code coverage
Enhancement: more Rubocop cops enabled
Enhancement: extract Contract class to contracts/contract.rb
Enhancement: extract FailureCallback module to contracts/contract/failure_callback.rb
Enhancement: better ErrorFormatter for KeywordArgs contract
Enhancement: many loops / conditional branches / old comments are improved / simplified
Enhancement: rename Contracts::Args -> C::SplatArgs for clearer intention (with deprecation warning)
Enhancement: remove Cucumber tests, because they are slow and inflexible
Enhancement: Rspec helper cleanup
Enhancement: Rspec tests with much less noise / no warnings
Code Diff: git diff 8889f13..03e9c56
https://github.com/ddd-ruby/contracts.ruby/compare/8889f13...03e9c56

v0.14.0

Enhancement: Add StrictHash contract - Fyodor #236
Bugfix: dont fail if something other than a hash is passed to a KeywordArgs - Dan Padilha #234
LICENSE ADDED: Simplified BSD (same as what is specified in the readme) - Charles Dale #233
Bugfix: fix constant looking when including a module that includes contracts (requires removing the check to see if contracts is already included) - Aditya Bhargava #232
Bugfix for err case when KeywordArgs and Proc are used together - Aditya Bhargava #230
Enhancement: Add DescendantOf contract - Miguel Palhas #227

Feature: add Regexp validator - Gert Goet #196
Docs: bootstrap cucumber/aruba/relish setup - Oleksii Fedorov #195
Bugfix: allow to extend module, that has Contracts or Contracts::Core included without harming current module/class Contracts functionality, see: #176 - Oleksii Fedorov #198
Enhancement: add include Contracts::Builtin to allow users to use builtin contracts without Contracts:: prefix together with include Contracts::Core - PikachuEXE #199

Enhancement: add include Contracts::Core that doesn't pollute the namespace as much as include Contracts - Oleksii Federov #185
Bugfix: fail if a non-hash is provided to a HashOf contract - Abe Voelker #190
Bugfix: bugfix for using varargs and Maybe[Proc] together - Adit Bhargava #188
Bugfix: make KeywordArgs fail if unexpected keys are passed in - Abe Voelker #187
Feature: range contract added - Oleksii Fedorov #184
Feature: enum contract added - Dennis Günnewig #181

Enhancement: make @pattern_match instance variable not render ruby warning. Required to use new aruba versions in rspec tests - Dennis Günnewig #179

Bugfix: make Maybe[Proc] work correctly - Simon George #142
Bugfix: make Func contract verified when used as return contract - Rob Rosenbaum #145
Bugfix: make Pos, Neg and Nat contracts handle non-numeric values correctly - Matt Griffin and Gavin Sinclair #147 #173
Enhancement: reduce user class pollution through introduction of contracts engine - Oleksii Fedorov #141
Feature: add builtin KeywordArgs and Optional contracts for keyword arguments handling - Oleksii Fedorov #151
Feature: recognize module as a class contract - Oleksii Fedorov #153
Feature: custom validators with Contract.override_validator - Oleksii Fedorov #159
Feature: add builtin RangeOf[...] contract - Gavin Sinclair #171

MAJOR fix in pattern-matching: If the return contract for a pattern-matched function fails, it should NOT try the next pattern-match function. Pattern-matching is only for params, not return values.
raise an error if multiple defns have the same contract for pattern matching.
New syntax for functions with no input params (the old style still works) Old way:
```
Contract nil => 1
def one
```
New way:
```
Contract 1
def one
```
Prettier HashOf contract can now be written like this: HashOf[Num => String]
Add SetOf contract
various small fixes

code refactored (very slight loss of performance, big increase in readability)
fail when defining a contract on a module without include Contracts::Modules
fixed several bugs in argument parsing, functions with complex params get contracts applied correctly now.
added rubocop to ci.
if a contract is set on a protected method, it should not become public.
fixed pattern matching when the multiple definitions of functions have different arities.
couple of new built-in contracts: Nat, Eq.
changed Invariant to invariant: invariant(:day) { 1 <= day && day <= 31 }
prettier error messages (Contracts::Num is now just Num, for example)
support for yard-contracts