v0.20.2

Changelog

• 1104fc5 Address issue #753
• 75e3ed5 Update functions/openapi/schema_type.go
• c2ec2c7 added nullable-enum-contains-null rule
• 9c68278 added constraint validation to schema type checking
• 1701286 address logic error
• 0cff4e1 adjusted to new XMLValidator interface
• a9b7c4e bump version of libopenapi-validator
• 95e5972 reduce complexity and clean up constraint checking