v1.6.0
#142 Optional extra arguments for custom error messages
#143 Add constraint factory
#192 Create .gitattributes
#194 bugfix: patternProperties raised errors when the pattern has slashes
#202 Fix CollectionConstraint to allow uniqueItems to be false
#204 Fix path output for required properties
#206 An email is a string, not much else.
#207 Fix non-6 digit microsecond date time formats
#209 RefResolver::$depth restoration after JsonDecodingException