Merge branch 'release/0.3.1' into develop
Initialize with class rules

This partially reverts 8d57863a1bcb53833c737b04fb7aca83252eb41c
Merge pull request #7 from cbandy/develop

Allow self-contained validators to accept new rules
Include inner exception when raising InvalidRule
Add RegularExpression and simple spec
Fix test for Ruby 1.9.2
Fix typo in valid_value? method name
Clarified error_key method's symbol name
Clarified Contributing section
Merge pull request #11 from olivierdagenais/ExplainInvalidRules

Include inner exception when raising InvalidRule
Merge pull request #13 from olivierdagenais/AddRegularExpressionRule

Add RegularExpression and simple spec
Merge pull request #12 from olivierdagenais/FixReadme

Fix readme
Bump version
Merge branch 'release/0.4.0'